5-Year longitudinal study of determinants of glycemic control for multi-ethnic Asian patients with type 2 diabetes mellitus managed in primary care

• A real-life non-interventional cohort study of multi-ethnic Asian patients with type 2 diabetes mellitus in a developed nation.
• Longitudinal data analysis of glycaemic control using Generalised Estimating Equation (GEE).
• Maintenance of glycaemic control amongst the cohort subjects within the first three years of review in primary care.
• Young patients of Malay or Indian ethnic groups and those treated with insulin, biguanide, AGI and thiazide were associated with deteriorating glycemic control after 2 years.

AimThis study aims to determine the risk factors associated with glycaemic control of ambulatory patients with type 2 diabetes mellitus (T2DM) who are managed in primary care.MethodThe data was retrieved from a primary care site within the Singapore Consortium of Cohort Studies-Diabetes Cohort (SCCS-DC). Demographic and clinical variables were described, in association with the risk of having a deteriorating glycaemic control (defined as an absolute increase of at least 1% HbA1c from one year to a subsequent year). Next, multivariate model was performed to define the independent effect of each factor. The longitudinal analysis of the HbA1c was performed using Generalised Estimating Equation (GEE).ResultsThe 5 year longitudinal data of 1256 patients (54% Chinese, 25% Malays, 12% Indians, 9% others) were analysed. Their mean HbA1c decreased by <0.1% in the initial 3 years, but increased thereafter. 12% of them had absolute HbA1c increment of ≥1% in the first year, and 22% over 5 years. Based on GEE analysis, insulin, was associated with an increase of HbA1c (≥1%) from one year to another (all p < 0.05). Compared with Chinese patients, Malays had higher HbA1c (+0.3%), Indians (+0.3%), and others (+0.2%), (all p < 0.01). Patients with retinopathy had higher HbA1c (+0.2%) and those with cataract had lower mean HbA1c (−0.2%) (p < 0.01).ConclusionMost cohort patients achieved glycaemic control within the initial 3 years. Patients of Malay and Indian ethnicity and those with retinopathy were associated with subsequent risk of glycaemic control deterioration. Those with cataract were associated with trend towards improved glycaemic control.