ABSTRACT
Introduction:
Type 2 diabetes mellitus increases the risk of atherosclerotic cardiovascular disease (ASCVD) and microvascular complications, which are further exacerbated by hypertension. This study examined the prevalence of uncontrolled blood pressure (BP) and its associated factors among diabetic patients in primary care clinics in Bahrain.
Methods:
A cross-sectional study was conducted among diabetic patients attending specialized primary care clinics in Bahrain. Data were extracted from electronic medical records, with uncontrolled BP defined as systolic BP ≥130 mmHg or diastolic BP ≥80 mmHg. Associations were analyzed using the Chi-square test, and logistic regression was used to calculate the unadjusted and adjusted odds ratios.
Results:
Among the 538 patients, 67% had uncontrolled BP. Patients aged >60 years (aOR = 1.68; 95% CI: 1.07–2.63), obese individuals (aOR = 1.72; 95% CI: 1.09–2.73), those on ≥3 antihypertensives (aOR = 2.52; 95% CI: 1.24–5.35), and those with elevated fasting blood sugar (aOR = 2.52; 95% CI: 1.24–5.35) had significantly higher odds of uncontrolled BP. Sex, lipid levels, and other comorbidities showed no significant association.
Discussion:
The high prevalence of uncontrolled BP is consistent with regional studies, but exceeds rates in high-income settings, possibly due to the use of stricter targets. Identified risk factors, including aging, obesity, and glycemic dysregulation, align with global trends and highlight challenges in managing resistant hypertension.
Conclusion:
Two-thirds of diabetic patients in Bahrain’s primary care clinics have uncontrolled BP, which is associated with older age, obesity, multiple antihypertensive medications, and poor glycemic control. These findings highlight the potential impact of integrated management strategies, weight management interventions, and more strict glucose control.
Keywords: Bahrain, blood pressure control, hypertension, primary care, Type 2 diabetes mellitus
Introduction
Type 2 Diabetes mellitus is marked by insulin resistance, insufficient insulin secretion, and hyperglycemia. It is particularly known for its microvascular complications, such as retinopathy, nephropathy, and neuropathy. Further it is also complicated by atherosclerotic cardiovascular diseases (ASCVD); that is acute coronary syndrome, myocardial infarction (MI), stroke, acute coronary syndrome, MI, angina, coronary or other arterial revascularization, stroke, transient ischemic attack, or peripheral arterial disease.[1]
Diabetes mellitus is a prevalent disease that affects an estimated 10.5 percent of adults globally, translating to around 530 million affected individuals worldwide.[2] In Bahrain, approximately 15% of the total population is afflicted by diabetes, and this number is anticipated to grow in the future decades.[3] Hypertension is another prevalent disease, affecting about 30% of the global population.[4] In the kingdom of Bahrain recent national survey reported a similar prevalence rate.[3]
Compared to the general population hypertension is more prevalent in patients with diabetes. Further hypertension is also a significant risk factor for ASCVD. When diabetes mellitus and hypertension coexist, the risk of ASCVD and microvascular complications increases.[5,6] As a result, strict hypertension control is generally advised for patients with diabetes. Multiple studies showed the beneficence of controlling the blood pressure (BP) in diabetic patients to reduce the risk of such complications.[5,7,8]
The optimal BP target for diabetic patients has been subject to continuous change, with various targets proposed over time. In the 2022 guidelines by the American Diabetes Association (ADA), the recommended BP readings were less than 140 mmHg systolic and 90 mmHg diastolic for diabetic patients without cardiovascular risk, like the targets set for the general population. For those with an elevated cardiovascular risk, more strict control was proposed; that is less than 130 mmHg systolic and 80 mmHg diastolic.[9] Nonetheless, the most recent ADA guideline released in 2023 proposed a lower threshold of control, to target a BP of less than 130 mmHg systolic and 80 mmHg diastolic in all diabetic patients.[5]
This approach is supported with many studies, including trails and meta-analyses. The ACCORD trail found that a strict control of BP reduces the risk of strokes.[10] Moreover, in patients with both a strict glycemic and BP control; the risk of major cardiovascular was significantly lower.[11] Multiple meta-analyses found similar results were a strict control of BP in high-risk patients (including diabetics), decreased the overall mortality and complications like ASCVD.[10,12,13]
There have been various studies examining the control rates of BP among diabetic patients, with results differing widely. In a study conducted in Iran and another in Malaysia, the control rate was 43% and 42%, respectively.[14,15] In Riyadh, the controlled rate was 28%.[16] A study conducted in Germany revealed a control rate of only 13%.[17] These varying rates highlight the ongoing challenge and importance of effectively managing hypertension in diabetic patients. Various risk factors were found to be associated with poor control of BP among diabetics were. While some studies focused on clinical characteristics, finding that high body mass index (BMI), total cholesterol and non-HDL cholesterol were associated with uncontrolled BP among diabetics.[14] Other studies focusing on personal and demographic characteristics identified older ages, male sex, longer duration of diabetes, number of comorbidities, and polypharmacy are predictive indicators for poor control.[15,16]
There have been limited local studies on BP control among diabetic patients in the primary care setting in the Kingdom of Bahrain; specifically, in the specialized Non-Communicable Diseases (NCD) clinic, and the Central Diabetes Clinic (CDC). The NCD clinic is an integral part of the primary health care system of Bahrain, located in all 27 health care centers of Bahrain. The main objective of the clinic is to manage adult patients with chronic disease (mainly patients with diabetes mellites and hypertension) aiming to reduce risk factors that lead to heart disease. Family physicians and a trained nurse run the clinic to provide chronic diseases patients with the necessary therapeutic and preventive care.[18] The central diabetes clinic focuses on the patients with diabetes, providing comprehensive care including preventive services in patient centered approach The clinic is run by family physicians and nurses specialized in Diabetes Mellitus.[19]
This study aims to assess the prevalence of uncontrolled BP readings and factors associated with poor control among diabetic patients attending the NCD and CDC primary care clinics in the Kingdom of Bahrain between 2022 and 2024.
Methods
Study design, setting and participants
This is a cross-sectional study investigating the prevalence of uncontrolled BP among patients with diabetes in the CDC and NCD in primary health centers in Bahrain. These clinics are specialized clinics located in primary health centers, where patients with diabetes mellitus can receive the optimal care. NCD clinics provide services to patients with chronic diseases aged 18 years and above. Family physicians and a trained nurse run it to provide the necessary therapeutic and preventive care. CDC is a specialized clinic connected to NCD run by family physicians, who have further training in managing Diabetes Mellitus. There is a written referral criteria to refer the patient from NCD to CDC and vice versa. All patients with a diabetes diagnosis are eligible to be included in the study, except for patients who received the service through Tele-consultation.
Sample size and sampling strategy
To calculate the required sample size, a prevalence of 60% for uncontrolled blood pressure among diabetic patients was assumed, based on published studies.[14,15] The calculation used a 95% confidence interval and a 5% margin of error. This calculation yielded a sample size of 369 patients. However, data collection continued, resulting in a larger sample size of 538 diabetic patients attending either of the clinics. A list of all the attendance records from both clinics for the year 2022 was retrieved from the electronic health system; and a simple random sample was obtained from the list.
Case definition
Based on the 2024 ADA guidelines, the target BP for patients with diabetes mellitus is below 130/80 mmHg.[20] Patients with a systolic BP of 130 mmHg or higher and/or a diastolic BP of 80 mmHg or higher were considered to have uncontrolled BP. Laboratory investigations were categorized according to ADA-recommended cutoffs as follows: HbA1c: 53 mmol/mol, fasting blood sugar (FBS): 7.2 mmol/L, LDL cholesterol: 2.6 mmol/L, HDL cholesterol: 1.02 mmol/L, and triglycerides (TG): 1.7 mmol/L.[21,22]
Data collection
Data were extracted from the electronic medical record system, i-Seha, using information from the most recent visit to the NCD or CD clinic. The collected data included demographic details, BP readings from the visit, comorbidities, antihypertensive medications, antidiabetic medications, lipid-lowering medications, and routine laboratory investigations.
Data analysis
The analysis was conducted using R version 4.4.2. Categorical variables were summarized as frequencies and percentages, and the Chi-square test was used to analyze associations between the potential risk factors and uncontrolled BP readings. To quantify the effect of risk factors on uncontrolled BP readings, unadjusted and adjusted odds ratios were calculated using a logistic regression model that included demographic factors and selected laboratory investigations.
Ethical consideration
Routinely collected data from Bahrain’s Primary Healthcare Centers were used for this study. The analyzed data were fully anonymized prior to receipt, with all identifying variables removed to ensure confidentiality. The study ethical approval was granted by Bahrain’s Primary Healthcare Centers Research Committee (IRB - PHCRC/TOR/0024/2023).
Results
Study sample
A total of 538 diabetic patients were enrolled in the study, with 311 (58%) from the NCD clinic and 223 (41%) from the CDC. Among these patients, 283 (53%) were female. The mean age of the participants was 61 ± 11 years. Regarding obesity 231 patients (43%) were classified as obese (BMI >30 kg/m²). Only 53 patients (10%) were reported as smokers; however, smoking data were missing for 83 patients (25%). The mean systolic blood pressure was 133 ± 19 mmHg, and the mean diastolic blood pressure was 74 ± 10 mmHg [Table 1].
Table 1.
Demographic characteristics of patients with diabetes visiting Bahrain primary care non-communicable diseases and central diabetes clinics
| Variable | Total1 n=538 | Uncontrolled BP Reading2 n=339 | Controlled BP Reading2 n=199 | P | |
|---|---|---|---|---|---|
| SEX | Female | 283 (53%) | 183 (65%) | 100 (35%) | 0.4 |
| Male | 255 (47%) | 156 (61%) | 99 (39%) | ||
| AGE | <60 years | 224 (42%) | 128 (57%) | 96 (43%) | 0.017 |
| >60 years | 314 (58%) | 211 (67%) | 103 (33%) | ||
| BMI | BMI<30 | 224 (42%) | 125 (56%) | 99 (44%) | |
| BMI>30 | 231 (43%) | 157 (68%) | 74 (32%) | 0.008 | |
| Missing | 83 (15%) | 57 | 26 | ||
| Smoking history | No | 352 (65%) | 225 (64%) | 127 (36%) | 0.2 |
| Yes | 53 (10%) | 29 (55%) | 24 (45%) | ||
| Missing | 133 (25%) | 85 | 48 |
BP=Blood pressure, BMI=body mass index. 1Number of observations with column percentages. 2Number of observations with row percentages; systolic blood pressure (SBP) over 130 mmhg or diastolic blood pressure (DBP) over 80 mmhg was considered as uncontrolled
Only 8 patients (1%) were classified as having type 1 diabetes mellitus. From the documented comorbidities in the electronic health record, the majority had a registered diagnosis of dyslipidemia (n = 425, 79%). Hypertension was documented in 341 (63%) patients, and renal disease in only 23 (4%) patients [Table 2].
Table 2.
Comorbidities of patients with diabetes visiting Bahrain primary care non-communicable diseases and central diabetes clinics
| variable | Total1 n=538 | Uncontrolled BP Reading2 n=339 | Controlled BP Reading2 n=199 | P | |
|---|---|---|---|---|---|
| Diabetes Type | Type 1 | 8 (1%) | 1 (12%) | 7 (88%) | 0.005 |
| Type 2 | 530 (99%) | 338 (64%) | 192 (36%) | ||
| Hypertension | No | 196 (36%) | 98 (50%) | 98 (50%) | <0.001 |
| Yes | 341 (63%) | 240 (70%) | 101 (30%) | ||
| Missing | 1 (0%) | 1 | 0 | ||
| Coronary heart disease | No | 489 (91%) | 311 (64%) | 178 (36%) | 0.3 |
| Yes | 48 (9%) | 27 (56%) | 21 (44%) | ||
| Missing | 1 (0%) | 1 | 0 | ||
| Congestive heart Failure | No | 533 (99%) | 335 (63%) | 198 (37%) | >0.9 |
| Yes | 4 (1%) | 3 (75%) | 1 (25%) | ||
| Missing | 1 (0%) | 1 | 0 | ||
| Dyslipidemia | No | 112 (21%) | 68 (61%) | 44 (39%) | 0.6 |
| Yes | 425 (79%) | 270 (64%) | 155 (36%) | ||
| Missing | 1 (0%) | 1 | 0 | ||
| Cerebrovascular disease | No | 532 (99%) | 333 (63%) | 199 (37%) | 0.2 |
| Yes | 5 (1%) | 5 (100%) | 0 (0%) | ||
| Missing | 1 (0%) | 1 | 0 | ||
| Renal disease | No | 514 (96%) | 323 (63%) | 191 (37%) | 0.8 |
| Yes | 23 (4%) | 15 (65%) | 8 (35%) | ||
| Missing | 1 (0%) | 1 | 0 | ||
| Hyperthyroidism | No | 533 (99%) | 336 (63%) | 197 (37%) | 0.6 |
| Yes | 4 (1%) | 2 (50%) | 2 (50%) | ||
| Missing | 1 (0%) | 1 | 0 | ||
| Hypothyroidism | No | 485 (90%) | 305 (63%) | 180 (37%) | >0.9 |
| Yes | 52 (10%) | 33 (63%) | 19 (37%) | ||
| Missing | 1 (0%) | 1 | 0 |
BP=Blood pressure. 1Number of observations with column percentages. 2Number of observations with row percentages; systolic blood pressure (SBP) over 130 mmhg or diastolic blood pressure (DBP) over 80 mmhg was considered as uncontrolled
Regarding medications actively prescribed, 167 patients (31%) were receiving insulin, and 459 patients (85%) were on an oral hypoglycemic agent. The most prescribed oral hypoglycemic was metformin (n = 371, 69%), followed by DPP-4 inhibitors (n = 282, 52%). For hypertension management, 324 patients (60%) received at least one type of antihypertensive medication: 116 patients (22%) were on one medication, and 121 patients (22%) on two medications. The most prescribed classes of antihypertensives were angiotensin-converting enzyme inhibitors (ACEIs) (n = 151, 28%) [Table 3].
Table 3.
Medications of patients with diabetes visiting Bahrain primary care non-communicable diseases and central diabetes clinics
| Variable | Total1 n=538 | Uncontrolled BP Reading2 n=339 | Controlled BP Reading2 n=199 | |
|---|---|---|---|---|
| Currently on insulin | No | 366 (68%) | 235 (64%) | 131 (36%) |
| Yes | 167 (31%) | 101 (60%) | 66 (40%) | |
| Missing | 5 (1%) | 3 | 2 | |
| On Oral Hypoglycemics | No | 73 (14%) | 41 (56%) | 32 (44%) |
| Yes | 459 (85%) | 294 (64%) | 165 (36%) | |
| Missing | 6 (1%) | 4 | 2 | |
| Metformin | No | 161 (30%) | 98 (61%) | 63 (39%) |
| Yes | 371 (69%) | 237 (64%) | 134 (36%) | |
| Missing | 6 (1%) | 4 | 2 | |
| Sulfonylurea | No | 283 (53%) | 166 (59%) | 117 (41%) |
| Yes | 249 (46%) | 169 (68%) | 80 (32%) | |
| Missing | 6 (1%) | 4 | 2 | |
| GLP 1 | No | 515 (96%) | 322 (63%) | 193 (37%) |
| Yes | 17 (3%) | 13 (76%) | 4 (24%) | |
| Missing | 6 (1%) | 4 | 2 | |
| DPP 4 | No | 250 (46%) | 149 (60%) | 101 (40%) |
| Yes | 282 (52%) | 186 (66%) | 96 (34%) | |
| Missing | 6 (1%) | 4 | 2 | |
| SGLT 2 | No | 467 (87%) | 290 (62%) | 177 (38%) |
| Yes | 64 (12%) | 44 (69%) | 20 (31%) | |
| Missing | 7 (1%) | 5 | 2 | |
| On Antihypertensive | No | 205 (38%) | 108 (53%) | 97 (47%) |
| Yes | 324 (60%) | 226 (70%) | 98 (30%) | |
| Missing | 9 (2%) | 5 | 4 | |
| ACEI | No | 380 (71%) | 226 (59%) | 154 (41%) |
| Yes | 151 (28%) | 108 (72%) | 43 (28%) | |
| Missing | 7 (1%) | 5 | 2 | |
| ARBS | No | 402 (75%) | 244 (61%) | 158 (39%) |
| Yes | 130 (24%) | 91 (70%) | 39 (30%) | |
| Missing | 6 (1%) | 4 | 2 | |
| CCB | No | 394 (73%) | 233 (59%) | 161 (41%) |
| Yes | 138 (26%) | 102 (74%) | 36 (26%) | |
| Missing | 6 (1%) | 4 | 2 | |
| Thiazaide | No | 490 (91%) | 306 (62%) | 184 (38%) |
| Yes | 41 (8%) | 28 (68%) | 13 (32%) | |
| Missing | 7 (1%) | 5 | 2 | |
| Thiazide Like | No | 471 (88%) | 288 (61%) | 183 (39%) |
| Yes | 55 (10%) | 44 (80%) | 11 (20%) | |
| Missing | 12 (2%) | 7 | 5 | |
| Beta Blocker | No | 429 (80%) | 267 (62%) | 162 (38%) |
| Yes | 103 (19%) | 68 (66%) | 35 (34%) | |
| Missing | 6 (1%) | 4 | 2 | |
| Sprironolatone | No | 527 (98%) | 333 (63%) | 194 (37%) |
| Yes | 5 (1%) | 2 (40%) | 3 (60%) | |
| Missing | 6 (1%) | 4 | 2 | |
| Other Diuretics | No | 508 (94%) | 322 (63%) | 186 (37%) |
| Yes | 18 (3%) | 10 (56%) | 8 (44%) | |
| Missing | 12 (2%) | 7 | 5 | |
| Number of Antihypertensive Medications | 0 | 214 (40%) | 113 (53%) | 101 (47%) |
| 1 | 116 (22%) | 81 (70%) | 35 (30%) | |
| 2 | 121 (22%) | 82 (68%) | 39 (32%) | |
| ≥3 | 87 (16%) | 63 (72%) | 24 (28%) | |
| On Lipid Lowering Agent | No | 107 (20%) | 66 (62%) | 41 (38%) |
| Yes | 425 (79%) | 269 (63%) | 156 (37%) | |
| Missing | 6 (1%) | 4 | 2 | |
| Statin | No | 107 (20%) | 66 (62%) | 41 (38%) |
| Yes | 425 (79%) | 269 (63%) | 156 (37%) | |
| Missing | 6 (1%) | 4 | 2 | |
| Ezetimibe | No | 529 (98%) | 333 (63%) | 196 (37%) |
| Yes | 4 (1%) | 3 (75%) | 1 (25%) | |
| Missing | 5 (1%) | 3 | 2 | |
| Adherence to medication | No | 21 (4%) | 14 (67%) | 7 (33%) |
| Yes | 480 (89%) | 302 (63%) | 178 (37%) | |
| Missing | 37 (7%) | 23 | 14 |
BP=Blood pressure, ACEI=angiotensin-converting enzyme inhibitor, ARBS=angiotensin receptor blockers, CCB=calcium channel blockers, SGLT2=sodium-glucose cotransporter-2, DPP4=dipeptidyl peptidase-4, GLP1=glucagon-like peptide-1 receptor agonist. 1Number of observations with column percentages. 2Number of observations with row percentages; systolic blood pressure (SBP) over 130 mmhg or diastolic blood pressure (DBP) over 80 mmhg was considered as uncontrolled
For laboratory investigations conducted before each visit, 235 patients (44%) had a FBS reading greater than 7.2 mmol/L and 299 patients (56%) had an HbA1c value greater than 53 mmol/mol. Regarding lipid profiles, 136 patients (25%) had an LDL reading above the cutoff of 2.6 mmol/L,275 patients (51%) an HDL level lower than 1.02 mmol/L, and 171 patients (32%) had a triglyceride (TG) reading greater than 1.7 mmol/L [Table 4].
Table 4.
Laboratory investigations of patients with diabetes comorbidities visiting Bahrain primary care non-communicable diseases and central diabetes clinics
| Variable | Total1 n=538 | Uncontrolled BP Reading2 n=339 | Controlled BP Reading2 n=199 | P | |
|---|---|---|---|---|---|
| Fasting Blood Sugaur | FBS <7.2 mmol/L | 234 (43%) | 131 (56%) | 103 (44%) | 0.004 |
| FBS >7.2 mmol/L | 235 (44%) | 162 (69%) | 73 (31%) | ||
| Missing | 69 (13%) | 46 | 23 | ||
| Hb A1c | Hb A1c <53 mmol/mol | 200 (37%) | 113 (57%) | 87 (44%) | 0.012 |
| Hb A1c >53 mmol/mol | 299 (56%) | 202 (68%) | 97 (32%) | ||
| Missing | 39 (7%) | 24 | 15 | ||
| LDL | LDL <2.6 mmol/L | 323 (60%) | 200 (62%) | 123 (38%) | 0.7 |
| LDL >2.6 mmol/L | 136 (25%) | 87 (64%) | 49 (36%) | ||
| Missing | 79 (15%) | 52 | 27 | ||
| HDL | HDL >1.02 mmol/L | 186 (35%) | 115 (62%) | 71 (38%) | 0.8 |
| HDL <1.02 mmol/L | 275 (51%) | 174 (63%) | 101 (37%) | ||
| Missing | 77 (14%) | 50 | 27 | ||
| TG | TG <1.7 mmol/L | 171 (32%) | 99 (58%) | 72 (42%) | 0.081 |
| TG >1.7 mmol/L | 294 (55%) | 194 (66%) | 100 (34%) | ||
| Missing | 73 (14%) | 46 | 27 | ||
| Cholesterol | Cholesterol | 465 (4.05±1.10) | 294 (4.12±1.12) | 171 (3.92±1.04) | 0.081 |
| Missing | 73 (14%) | 45 | 28 | ||
| Hb | Hb | 388 (12.79±1.84) | 241 (12.71±1.82) | 147 (12.90±1.87) | 0.3 |
| Missing | 150 (28%) | 98 | 52 | ||
| ACR | ACR | 201 (29±209) | 125 (43±264) | 76 (5±15) | 0.066 |
| Missing | 337 (63%) | 214 | 123 | ||
| eGFR | eGFR | 395 (87±29) | 253 (87±29) | 142 (89±28) | 0.6 |
| Missing | 143 (27%) | 86 | 57 | ||
BP=Blood pressure, FBS=fasting blood sugar, HbA1c=hemoglobin A1c, LDL=low-density lipoprotein, HDL=high-density lipoprotein, TG=triglycerides, ACR=albumin-to-creatinine ratio, eGFR=estimated glomerular filtration rate. 1Number of observations with column percentages. 2Number of observations with row percentages; systolic blood pressure (SBP) over 130 mmhg or diastolic blood pressure (DBP) over 80 mmhg was considered as uncontrolled
Prevalence of uncontrolled blood pressure readings
The prevalence of uncontrolled BP readings among the enrolled diabetic patients was 67% (n = 339). The prevalence of uncontrolled BP readings was similar between females (n = 183, 65%) and males (n = 156, 61%) (P value = 0.4). Approximately 67% (n = 211) of patients aged above 60 years had uncontrolled BP measurements, compared to 57% (n = 128) in those below 60 years (P value = 0.017). Patients with a BMI greater than 30 kg/m² (n = 157, 68%) had also a higher prevalence of uncontrolled BP readings compared to those with a BMI less than 30 kg/m² (n = 125, 56%) (P value = 0.008) [Table 1].
Approximately 70% (n = 240) of patients with a recorded diagnosis of hypertension had an uncontrolled BP reading, compared to around 50% (n = 98) of those without such a diagnosis (P value < 0.001). There was no evidence of a difference in the prevalence of high BP readings among patients with other recorded comorbidities such as dyslipidemia, coronary artery disease (CAD), renal disease, and hypothyroidism [Table 2].
Stratifying the prevalence of uncontrolled BP readings by blood glucose control, patients with a high FBS level had a prevalence of 69% (n = 162), compared to 56% (n = 131) in those with better control (P value = 0.004). According to HbA1c levels, around 68% (n = 202) of patients with high HbA1c had an uncontrolled BP reading, compared to 57% (n = 113) in those with lower levels (P value = 0.012) [Table 4].
Factors associated with uncontrolled blood pressure readings
Investigating the effect of factors—including sex, age, BMI, number of antihypertensive medications, FBS level, HbA1c level, LDL level, HDL level, and TG level—on the prevalence of uncontrolled BP, unadjusted odds ratios were calculated. Patients above the age of 60 had 1.54 times the odds of having an uncontrolled BP reading compared to those below 60 (OR 1.54; 95% CI, 1.08–2.19). Compared to those not on antihypertensive medications, patients on one medication had 2.07 times the odds (OR 2.07; 95% CI, 1.29–3.37), those on two medications had 1.88 times the odds (OR 1.88; 95% CI, 1.18–3.01), and those on three or more had 2.35 times the odds (OR 2.35; 95% CI, 1.38–4.09). Patients with a high HbA1c had 1.6 times the odds (OR 1.60; 95% CI, 1.11–2.32) compared to those with a normal HbA1c, and those with a high FBS had 1.74 times the odds (OR 1.74; 95% CI, 1.20–2.55) compared to those with normal FBS readings [Table 5].
Table 5.
Multivariate logistic regression analysis for factors related to uncontrolled blood pressure readings among patients with diabetes
| Variable | Subcategory | Unadjusted OR (95% CI) | Adjusted OR (95% CI) |
|---|---|---|---|
| Sex | Male | 1 | 1 |
| Female | 1.16 (0.82 to 1.65) | 0.93 (0.58 to 1.49) | |
| Age | <60 years | 1 | 1 |
| >60 years | 1.54 (1.08 to 2.19) | 1.68 (1.07 to 2.63) | |
| BMI | <30 | 1 | 1 |
| >30 | 1.68 (1.15 to 2.47) | 1.72 (1.09 to 2.73) | |
| Number of Ant-ihypertensive Medications | 0 | 1 | 1 |
| 1 | 2.07 (1.29 to 3.37) | 1.65 (0.9 to 3.04) | |
| 2 | 1.88 (1.18 to 3.01) | 1.73 (0.96 to 3.16) | |
| ≥3 | 2.35 (1.38 to 4.09) | 2.52 (1.24 to 5.35) | |
| LDL level | LDL <2.6 mmol/L | 1 | 1 |
| LDL>2.6 mmol/L | 1.09 (0.72 to 1.66) | 1.18 (0.71 to 1.97) | |
| HDL level | HDL >1.02 mmol/L | 1 | 1 |
| HDL <1.02 mmol/L | 1.06 (0.72 to 1.56) | 1.23 (0.76 to 2) | |
| TG level | TG <1.7 mmol/L | 1 | 1 |
| TG >1.7 mmol/L | 1.41 (0.96 to 2.08) | 1.23 (0.77 to 1.96) | |
| HbA1C level | Hb A1c <53 mmol/mol | 1 | 1 |
| Hb A1c >53 mmol/mol | 1.6 (1.11 to 2.32) | 1.21 (0.74 to 1.98) | |
| FBS level | FBS <7.2 mmol/L | 1 | 1 |
| FBS >7.2 mmol/L | 1.74 (1.2 to 2.55) | 1.8 (1.1 to 2.96) |
BMI=Body mass index, LDL=low-density lipoprotein, HDL=high-density lipoprotein, TG=triglycerides, HbA1c=hemoglobin A1c, FBS=fasting blood sugar
After adjusting for potential confounders, those above 60 years old had an odds ratio of 1.68 (aOR 1.68; 95% CI, 1.07–2.63). Patients with a BMI >30 kg/m² had 1.72 times the odds of having an uncontrolled BP (aOR 1.72; 95% CI, 1.09–2.73). Following adjustment, only patients on three or more antihypertensive medications had a significantly higher odds compared to those not on medications (aOR 2.52; 95% CI, 1.24–5.35). While high HbA1c levels did not have a significant association after adjustment, patients with high FBS levels had 2.52 times the odds (aOR 2.52; 95% CI, 1.24–5.35) of having an uncontrolled BP reading [Table 5].
Discussion
This study examined the prevalence of uncontrolled BP among patients with diabetes in primary care settings in the Kingdom of Bahrain, recognizing that uncontrolled BP in this population significantly increases the risk of complications. In our findings, approximately 67% of diabetic patients attending specialized primary care clinics had elevated BP readings. This rate was slightly lower than that reported in a study conducted in the Kingdom of Saudi Arabia (KSA), where 71.8% of patients had uncontrolled BP, and in Malaysia, where the prevalence of uncontrolled BP ranged from 58% to 77% in diabetic patients.[15,16,23] Conversely, studies from the United States of America (USA), Ethiopia and India reported lower rates of uncontrolled BP, at approximately 60%.[24,25,26] It is important to consider the context of these studies when making comparisons. For instance, some studies were conducted in hospital-based settings, and many used the previous BP threshold of 140/90 mmHg for defining uncontrolled BP. In contrast, more recent guidelines adopt a stricter cutoff of 130/80 mmHg, which may impact prevalence estimates.[20]
Approximately 63% of the patients in our study were registered as having hypertension. This prevalence was slightly higher than the rates reported in similar studies, such as 53% in India and 57% in Malaysia.[23,25] In Iran, the prevalence of hypertension among patients with diabetes was estimated to be lower, at 45%.[27] This could be attributed to differences to a higher prevalence of hypertension in the community. The most used antihypertensive medication among diabetic patients in our study was an ACEI, consistent with findings from other studies.[23,24] However, a study conducted in the KSA reported that the most frequently used antihypertensive medication was a CCB, followed by an ACEI.[16]
In examining factors associated with poor BP control in patients with diabetes, we identified old age (over 60 years), obesity, the use of three or more antihypertensive medications, and FBS as significant predictors of uncontrolled BP. The role of sex in BP control remains inconclusive; while our study found no association, consistent with findings from studies in Ethiopia and Malaysia, research from Saudi Arabia identified male sex as a risk factor, whereas a study in the United States reported female sex as a risk factor for poor BP control.[16,23,24,26] Despite variations in the age thresholds used across studies (ranging from 50 to 65 years), evidence consistently linked aging to lower BP control rates among diabetic patients.[16,23,24,25,26] Similarly, higher BMI was consistently associated with an increased likelihood of uncontrolled BP across studies.[16,24,25] Patients on three or more antihypertensive medications had significantly higher rates of uncontrolled BP, reflecting challenges in managing resistant hypertension a finding consistent with studies from the USA.[26] Further the study conducted in KSA identified polypharmacy as a predictor of uncontrolled BP.[16] Our study also identified uncontrolled FBS to be linked with poor BP control, aligning with findings from Ethiopia and the USA.[24,26] These results underscore the multifactorial nature of BP management in diabetic patients and the need for comprehensive interventions targeting these risk factors. In a recent meta-analysis, multidisciplinary, team-based care was shown to reduce the risk of uncontrolled blood pressure in hypertensive patients, suggesting that similar strategies could be adapted to improve BP control among diabetic populations.[28]
This study had several strengths. First, it included all primary care health centers across the Kingdom, providing a comprehensive overview. Second, utilizing data from the specialized NCD and CD clinics ensured greater consistency and completeness, as data were systematically entered by specialized nurses during each visit. Third, by relying on routinely collected data, the study minimized recall bias among patients. However, the study also had limitations. Utilizing a cross-sectional design, we could not establish temporality between certain risk factors and poor BP control. Additionally, the reliance on routinely collected data, which was not specifically designed for research purposes, resulted in missing variables such as the duration of diabetes and information on interventions like diet and lifestyle modifications. Finally, restricting the sample to patients from specialized clinics may limit the generalizability of the findings, as patients attending general clinics were not included.
Conclusion
To conclude, our cross-sectional study underscores the high prevalence of uncontrolled blood pressure among diabetic patients in Bahrain’s specialized primary care clinics. Key factors associated with poorly controlled blood pressure include older age, obesity, the use of multiple antihypertensive agents, and poor glycemic control. Although the study had some limitations inherent to the study design; the findings underscore the potential benefits of integrated management strategies, weight management interventions, and stricter glucose control.
Author contributions’ statement
All authors have contributed significantly to this study and have reviewed and approved the final manuscript. Dr. Adel Salman AlAlsayyad, Dr. Ebrahim Matar, and Dr. Zahra Salman Zabar conceptualized the study, formulated the research question, and designed the methodology. Dr. Adel Salman AlAlsayyad, Dr. Ebrahim Matar and Dr. Zahra Salman Zabar conducted the formal data analysis and interpretation. Dr. Adel Salman AlAlsayyad, Dr. Ebrahim Matar, Dr. Zahra Salman Zabar, and Dr. Fatima Al Nooh were responsible for drafting the manuscript, including the introduction, methods, results, and discussion. Dr. Afrah Saeed Isa, Dr. Masooma Jaafar Ali, and Dr. Zainab Jaffar Ali participated in data collection, curation, and verification. All authors also contributed to critical revision of the manuscript. Dr. Adel Salman Alal Sayyad supervised and managed the study. All authors agree to be accountable for all aspects of the work.
Ethical approval statement
This study was reviewed and approved by the Primary Health Care Research Committee, Bahrain, under the IRB approval number PHCRC/TOR/0024/2023, granted on October 5, 2023.
Conflict of interest statement
No financial or non-financial benefits have been received or will be received from any party directly or indirectly related to this article’s subject.
Acknowledgments
The authors would like to extend their sincere gratitude to all the primary care staff, particularly the dedicated doctors and nurses at the Central Diabetes Clinic (CDC) and the Non-Communicable Diseases (NCD) Clinic. Without their collective efforts and dedication to patient’s care, the successful completion of this research would not have been possible.
Funding Statement
Nil.
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