Table 3. Association of CKD stages 3 to 5 (GFR <60) with demographic characteristics, BMI, and history of selected diseases in logistic regression models.
| Variable | GFR ≥90 (%)n = 1240 | CKD stages 3–5 (%)n = 165 | Crude OR(95% CI) | Adjusted OR(95% CI) a | Adjusted OR(95% CI) b |
| Age, year (continuous) | - | - | 1.12 (1.10–1.14) | 1.13 (1.11–1.15) | 1.13 (1.11–1.15) |
| Sex | |||||
| Women | 721 (58.2) | 104 (63.0) | Reference | Reference | Reference |
| Men | 519 (41.8) | 61 (37.0) | 0.81 (0.58–1.14) | 0.24 (0.16–0.38) | 0.28 (0.18–0.45) |
| Ethnicity | |||||
| Sistani | 516 (41.6) | 58 (35.2) | Reference | Reference | Reference |
| Turkmen | 254 (20.5) | 40 (24.2) | 1.40 (0.91–2.15) | 0.96 (0.56–1.64) | 0.83 (0.47–1.45) |
| Fars | 301 (24.3) | 42 (25.5) | 1.24 (0.81–1.89) | 0.99 (0.58–1.68) | 0.78 (0.44–1.38) |
| Other | 169 (13.6) | 25 (15.1) | 1.32 (0.80–2.17) | 1.01 (0.54–1.90) | 0.72 (0.37–1.40) |
| Marital Status | |||||
| Married | 845 (68.2) | 130 (78.8) | Reference | Reference | Reference |
| Single | 354 (28.5) | 2 (1.2) | 0.04 (0.01–0.15) | 0.42 (0.08–2.12) | 0.52 (0.10–2.65) |
| Widow/divorced | 41 (3.3) | 33 (20.0) | 5.23 (3.19–8.58) | 0.80 (0.42–1.53) | 0.75 (0.39–1.47) |
| Education | |||||
| No school | 238 (13.2) | 114 (69.1) | Reference | Reference | Reference |
| Primary school | 171 (13.8) | 29 (17.6) | 0.35 (0.23–0.57) | 1.37 (0.78–2.41) | 1.22 (0.68–2.18) |
| Middle school | 150 (12.1) | 8 (4.8) | 0.11 (0.05–0.23) | 1.79 (0.70–2.56) | 1.58 (0.61–4.05) |
| High school | 514 (41.4) | 10 (6.1) | 0.04 (0.02–0.08) | 1.56 (0.61–3.94) | 1.48 (0.57–3.83) |
| University | 167 (13.5) | 4 (2.4) | 0.05 (0.02–0.14) | 1.63 (0.49–5.40) | 1.43 (0.43–4.80) |
| BMI | |||||
| <18.5 | 100 (48.0) | 2 (33.3) | 0.21 (0.05–0.90) | 0.44 (0.09–2.13) | 0.46 (0.08–2.20) |
| 18.5–24.9 | 595 (8.0) | 55 (1.2) | Reference | Reference | Reference |
| 25–29.9 | 338 (27.3) | 58 (35.2) | 1.86 (1.25–2.75) | 1.55 (0.93–2.57) | 1.57 (0.78–2.19) |
| ≥30 | 207 (19.7) | 50 (30.3) | 2.61 (1.73–3.95) | 1.78 (1.04–3.05) | 1.35 (0.77–2.36) |
| P for trend | <0.001 | 0.01 | 0.15 | ||
| Diabetes c | |||||
| Self-reported | 161 (13.0) | 32 (19.4) | 1.61 (1.06–2.45) | 1.70 (1.00–2.86) | 1.13 (0.65–1.98) |
| FBS ≥110 mg/dL | 116 (9.4) | 43 (26.1) | 3.42 (2.30–5.08) | 1.24 (0.76–2.00) | 0.94 (0.56–1.57) |
| Any criteria | 225 (18.2) | 54 (32.7) | 2.19 (1.54–3.13) | 1.47 (0.94–2.30) | 1.07 (0.66–1.72) |
| Hypertension c | |||||
| Self-reported | 182 (14.7) | 71 (43.0) | 4.39 (3.11–6.21) | 3.16 (2.02–4.95) | 2.85 (1.77–4.59) |
| Sys ≥140 or dias ≥90 mmHg | 243 (19.6) | 83 (50.3) | 4.15 (2.97–5.81) | 1.43 (0.93–2.18) | 1.26 (0.81–1.94) |
| Any criteria | 356 (28.7) | 100 (60.6) | 3.80 (2.71–5.33) | 2.64 (1.50–2.78) | 1.61 (1.04–2.50) |
| IHD c | 87 (7.0) | 39 (23.6) | 4.10 (2.70–6.24) | 2.73 (1.55–4.81) | 1.73 (0.93–3.21) |
| MI c | 47 (3.8) | 13 (7.9) | 2.17 (1.15–4.10) | 2.69 (1.14–6.32) | 1.55 (0.61–3.92) |
Abbreviations: BMI, body mass index (kg/m2); CI, confidence interval; CKD, chronic kidney disease; dias, diastolic blood pressure; FBS, fasting blood sugar; GFR, glomerular filtration rate (ml/min/1.73 m2); IHD, ischemic heart disease; MI, myocardial infarction; OR, odds ratio; sys, systolic blood pressure.
Adjusted for sex and age (categorical variable). Sex variable was only adjusted for age and vice versa.
Adjusted for sex, age (categorical variable, as Table 1), and BMI (categorical variable), self-reported diabetes mellitus, and self-reported hypertension. When one of these possible confounders was the variable of interest, the adjustments were made for the other possible confounders. None of the diabetes and hypertension variables were adjusted for self-reported diabetes and self-reported hypertension, respectively.
The reference groups included those who did not have the respective condition.