Youth onset Type 2 diabetes and elevated cardiovascular disease risk- a registry based case-control study from India (AD-1545)

Background and aim: Cardiovascular diseases (CVD) are one of the leading causes of mortality among youth onset diabetes. Being a recent entity, there are limited data on the CVD risk factor profile of youth with type 2 diabetes (age at diagnosis≤25 years). The aim of this study was to estimate the prevalence of traditional cardiovascular risk factors among youth onset type 2 diabetes and to compare with the general population without diabetes.
Methods: A case-control study was conducted to compare the CVD risk factor profile of youth onset diabetes patients (aged 20 years and above) with their age, gender and geographic location matched (frequency matching) controls without diabetes. People with diabetes were recruited from the Chennai reporting centre of the Registry of people with diabetes in India with young age at the onset (YDR). The control population was selected from the CARRS (Cardio metabolic Risk Reduction in South Asia) cohort from Chennai, India. Non diabetic status of the control subjects was confirmed by fasting plasma glucose values. Both YDR and CARRS used similar standard methodologies to quantify the behavioural, anthropometric and biochemical risk factors of CVD. Current smoking and alcohol use was based on self-report. Fruit and vegetable consumption was evaluated as the total number of times per day that a participant ate fruits and green leafy vegetables. For the analysis, fruit and vegetable consumption frequencies were categorized in to tertiles.  National Cholesterol Education Program Adult Treatment Panel [NCEP-ATP] III cut-offs were used to define overweight (BMI ≥25 and <30 kg/m2 ), obesity (BMI ≥30 kg/m2) and underweight (BMI<18.5 kg/m2 ). Waist circumference was categorized using both IDF and NCEP criteria. Abdominal obesity was defined as waist to hip ratio (WHR)> 0.90 for men and >0.85 for women. Pre hypertension and hypertension were defined using the Joint National Committee VII criteria (systolic blood pressure (SBP) ≥ 140 mm Hg and/or diastolic blood pressure (DBP) ≥ 90 mm Hg or on blood pressure lowering medication. If the participants had total cholesterol (TC) ≥200mg/dl or cholesterol lowering medication, they were labeled as hypercholesterolemic. Dyslipidemia was defined as total cholesterol ≥ 200mg/dl or LDL ≥ 130 mg/dl or HDL (<40mg/dl for men and <50mg/dl for women) or triglycerides ≥ 150mg/dl or on cholesterol lowering medication.  
Results: Current smoking and alcohol use was significantly higher in people without diabetes. Type 2 diabetes patients consumed more fruits and vegetables than their non-diabetic counter parts. However, there was low level of physical activity among youth with type 2 diabetes compared to control subjects. Youth onset type 2 diabetes patients had high prevalence (95% CI) of both generalized [21.4% (16.1, 27.8) vs 10.2% (7.6, 13.6)] and abdominal obesity [75.7% (68.7, 81.6) vs 49.2% (44.3, 54.4)]. The prevalence (95% CI) of hypertension among type 2 diabetes patients was three times higher than that of their age and gender matched controls [47.7% (40.7, 54.9) vs 13.9% (10.7, 18.0)]. Despite low mean levels of lipid parameters, the prevalence(95% CI) of dyslipidaemia, which took in to account medication use was significantly higher among patients with youth onset type 2 diabetes [92.0% (87.2, 95.2)] compared to controls [79.1% (74.7, 82.9].  Overall, patients with type 2 diabetes had a less favourable CVD risk profile with a total of 12.7 % had four or more risk factors, compared with 6.6% of control population. Type 2 diabetes patients had an average 2.4 risk factors compare to 1.8 among control subjects (p<0.0001). There was a significant gender difference in the clustering of risk factors in type 2 diabetes. The prevalence of four or more CVD risk factors in women (17.9 %) was significantly higher than that of men (17.9%  vs 7.0% ; p<0.001).
Discussion: This study found that the patients with youth onset diabetes had an adverse cardiovascular profile compared to the control population without diabetes. The high clustering of CVD risk factors in type 2 diabetes call for urgent secondary prevention strategies to curtail the burden of CVD’s in this young  productive population.

Youth onset type 2 diabetes and elevated cardiovascular disease risk: a registry based case-control study from India