Table 1.
Characteristics of the study population in the year following the diagnosis of type 2 diabetes stratified by whether individuals were tested and reached detection thresholds for pre-diabetes before the diagnosis of type 2 diabetes
| Total | No glycemic measures recorded before the diagnosis of T2D | Glycemic values within the normal range before the diagnosis of T2D | Pre-diabetes detected before the diagnosis of T2D | P value | |
| N | 159 736 | 93 949 | 21 902 | 43 885 | |
| % | 58.8 | 13.7 | 27.4 | ||
| Type of glycemic measures recorded before diagnosis of T2D (%) | |||||
| FPG | 82.1 | 74.4 | |||
| HbA1C | 38.4 | 58.2 | |||
| OGTT | 4.5 | 22.6 | |||
| Multiple tests | 23.7 | 53 | |||
| Time from testing to diagnosis of T2D, months; mean (SD) | 33.0 (6.1) | 33.1 (6.0) | 33.0 (6.2) | ||
| Female (%) | 49.2 | 48.8 | 55.6 | 46.7 | <0.001* |
| Age, years (SD) | 61.5 (14.4) | 60.2 (14.8) | 61.3 (14.8) | 64.3 (12.6) | <0.001† |
| Ethnicity (%) | |||||
| White | 83.0 | 82.7 | 84.5 | 82.9 | <0.001* |
| South Asian | 3.6 | 3.1 | 4.3 | 4.3 | <0.001* |
| Black | 2.4 | 2.2 | 3.1 | 2.7 | |
| Other | 3.1 | 2.9 | 3.4 | 3.3 | |
| Unknown | 7.9 | 9.2 | 4.7 | 6.9 | |
| Smoking status (%) | |||||
| Non-smoker | 35.4 | 36.8 | 35.8 | 32.3 | <0.001* |
| Ex-smoker | 51.6 | 43.4 | 46.3 | 51.6 | |
| Current smoker | 16.1 | 19.8 | 17.9 | 16.1 | |
| HbA1c at diagnosis, mmol/mol; mean (SD) | 55.2 (20.7) | 59.4 (20.8) | 47.0 (19.1) | 50.4 (18.9) | <0.001† |
| BMI, kg/m2; mean (SD) | 30.30 (6.7) | 30.0 (6.7) | 29.7 (7.0) | 31.3 (6.5) | <0.001† |
| SBP, mm Hg; mean (SD) | 136.4 (15.9) | 136.4 (16.6) | 134.0 (15.7) | 137.4 (14.3) | <0.001† |
| DBP, mm Hg; mean (SD) | 79.7 (9.4) | 80.1 (9.6) | 78.7 (9.3) | 79.5 (8.8) | <0.001† |
| Total cholesterol, mmol/L; mean (SD) | 5.1 (1.1) | 5.2 (1.1) | 5.0 (1.1) | 4.9 (1.1) | <0.001† |
| No of chronic diseases; mean (SD) | 2.7 (2.0) | 2.4 (1.9) | 3.2 (2.1) | 3.1 (2.0) | <0.001† |
| Medications (%) | |||||
| Anti-hypertensive | 53.8 | 47.5 | 53.2 | 67.6 | <0.001* |
| ACEi/ARBs | 39.0 | 34.1 | 37.9 | 50.2 | <0.001* |
| Anti-lipid medications | 49.6 | 44.2 | 45.1 | 63.3 | <0.001* |
| Anti-diabetic‡ | 38.4 | 44.7 | 19.5 | 34.3 | <0.001* |
| Biguanides | 34.6 | 39.8 | 17.0 | 32.3 | <0.001* |
| Sulfonylureas | 8.5 | 11.4 | 3.8 | 4.5 | <0.001* |
| Insulin | 2.7 | 3.5 | 2.1 | 1.2 | <0.001* |
| Other | 0.1 | 0.1 | 0.1 | 0.2 | 0.015* |
| Anti-platelet | 27.0 | 24.2 | 26.3 | 33.1 | <0.001* |
| No of primary care visits in the year before T2D diagnosis; mean (SD) | 12.9 (11.7) | 11.1 (10.9) | 16.8 (13.5) | 14.7 (11.6) | <0.001§ |
| Index of Multiple Deprivation quintiles (%) | |||||
| 1 Q—least deprived | 14.1 | 14.6 | 12.6 | 13.7 | <0.001* |
| 2 Q | 19.1 | 19.5 | 19.1 | 18.2 | <0.001* |
| 3 Q | 19.0 | 19.1 | 17.9 | 19.4 | |
| 4 Q | 22.3 | 21.1 | 23.7 | 24.2 | |
| 5 Q—most deprived | 25.6 | 25.8 | 26.7 | 24.5 | |
Results are presented using WHO/International Expert Committee criteria for the definition of pre-diabetes. Clinical data within 3 years before the diagnosis of type 2 diabetes were used to define the detection of pre-diabetes. P values from χ2, ANOVA, and Kruskal-Wallis tests, as appropriate, are reported for comparison between the three groups defined by testing and detection of pre-diabetes.
WHO/ International Expert Committee criteria to define pre-diabetes: FPG: 6.1–6.9 mmol/L; OGTT 7.8–11.1 mmol/L; HbA1c 42 to 47 mmol/mol or 6.0%–6.4%.
*χ2 test was performed to assess the unadjusted difference between groups.
†ANOVA test was performed to assess the unadjusted difference between groups.
‡If an individual was prescribed multiple medications from different anti-diabetic classes, each class was considered (eg, for an individual who was prescribed biguanides and sulfonylureas in the year following the diagnosis of type 2 diabetes, data were recorded as follows: anti-diabetic YES; biguanides YES; sulfonylureas YES; insulin NO; other anti-diabetic NO).
§Kruskal-Wallis test was performed to assess the unadjusted difference between groups.
ACEi, ACE inhibitor; ARB, angiotensin II receptor blocker; BMI, body mass index; DBP, diastolic blood pressure; FPG, fasting plasma glucose; OGTT, oral glucose tolerance test (2 hours after 75 g glucose load); SBP, systolic blood pressure; T2D, type 2 diabetes.