Undiagnosed diabetes, hypertension, and hypercholesterolaemia in an overweight or obese population: implications for cardiovascular disease risk screening programme

Introduction Establishing the burden of undiagnosed CVD risk factors is critical to monitoring public health efforts related to screening and diagnosis. Objective To assess the proportion and determinants of undiagnosed diabetes, hypertension, and hypercholesterolaemia, among overweight or obese adults. Methods A sample of 1200 participants aged 35-64 years with a BMI >= 25 kg/m(2) was selected from the Colombo district. Data were collected through a questionnaire, anthropometry, blood pressure measurement, and blood sampling for fasting plasma glucose, HbA1c, and lipid profile. Undiagnosed diabetes, hypertension, and hypercholesterolaemia were defined as fasting plasma glucose >= 126 mg/dL or HbA1c >= 6.5%; systolic blood pressure >= 140 mmHg or diastolic blood pressure >= 90 mmHg; total cholesterol >= 240 mg/dl respectively, in a person without a previous diagnosis. Multiple logistic regression analyses were carried out to identify determinants. Results The prevalence (95%CI) of diabetes was 28.0% (25.5, 30.5), hypertension, 33.4% (30.7, 36.1) and hypercholesterolaemia, 31.9% (29.2, 34.5). The proportion of undiagnosed diabetes was 13.8% (11.9, 15.8), undiagnosed hypertension 11.3% (9.5, 13.1), and undiagnosed hypercholesterolaemia 17.8% (15.6, 19.9). Undiagnosed cases accounted for almost half of all diabetes cases, one-third of all hypertension cases, and more than half (56%) of all high cholesterol cases. The key determinants for undiagnosed CVD risk were: male sex, low or middle income, rural residence, and relatively younger age. Conclusion CVD screening programmes should be tailored to target populations based on these determinants and provide basic diagnostic facilities in all health centres. The 'proportion undiagnosed' in the population may be a useful indicator to evaluate their effectiveness.