Incidence of Type 2 diabetes in England and its association with baseline impaired fasting glucose: The Ely study 1990-2000

• Published in: Diabetic medicine Vol. 24; no. 2; pp. 200 - 207
• Main Authors: Forouhi, N. G., Luan, J., Hennings, S., Wareham, N. J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.02.2007; Blackwell
• Subjects: Adult; Aged; Biological and medical sciences; diabetes; Diabetes Mellitus, Type 2 - epidemiology; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; England - epidemiology; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Glucose Tolerance Test; Humans; Hypoglycemia - epidemiology; impaired fasting glucose; Incidence; Longitudinal Studies; Male; Medical sciences; Middle Aged; Prevalence; Risk Factors; England; United Kingdom; Great Britain; Europe; Endocrinopathy; Type 2 diabetes; impaired fasting glucose; 1990-2000; Metabolic diseases; Fast; Epidemiology; diabetes; Glycemia; Incidence
• DOI: 10.1111/j.1464-5491.2007.02068.x
• ISSN: 0742-3071

Aim  To determine the incidence of Type 2 diabetes and to examine the effect of different cut‐points for impaired fasting glucose (IFG) on diabetes incidence. Methods  Population‐based longitudinal study (1990–2000) with clinical, anthropometric and biochemical measurements, including an oral glucose tolerance test (OGTT), in 1040 non‐diabetic adults aged 40–69 years at baseline. Baseline glucose status was defined as normoglycaemia < 5.6, IFG‐lower 5.6–6.0 and IFG‐original 6.1–6.9 mmol/l. The all‐IFG group included fasting glucose values of 5.6–6.9 mmol/l. Results  The 10‐year cumulative incidence of diabetes was 7.3 per 1000 person‐years. Diabetes incidence was 2.4 [95% confidence interval (CI) 1.2, 4.8], 6.2 (4.0, 9.8) and 17.5 (12.5, 24.5) per 1000 person‐years in those with normoglycaemia, IFG‐lower and IFG‐original, respectively. Compared with normoglycaemia, the age/sex‐adjusted risk [hazard ratio (HR) and 95% CI] for incident diabetes was greatest in the IFG‐original category (HR 6.9; 3.1, 15.2) and increased to a lesser degree in the IFG‐lower (HR 2.5; 1.1, 5.7) and all‐IFG categories (HR 4.1; 1.9, 8.7). When adjusted for confounding factors, the magnitude and direction of associations persisted, with HR 1.9, 4.4 and 2.9, for the categories IFG‐lower, IFG‐original and all‐IFG, respectively. Conclusions  Diabetes incidence is more strongly related to IFG defined as fasting glucose between 6.1 and 6.9 mmol/l than to the lower category of 5.6–6.0 mmol/l, or entire range of 5.6–6.9 mmol/l. Future studies should examine the association of IFG with cardiovascular outcomes, but for diabetes risk our study supports the use of the IFG cut‐point at 6.1 mmol/l.