Regularity of follow-up, glycemic burden, and risk of microvascular complications in patients with type 2 diabetes: a 9-year follow-up study

To assess the relationship between regularity of follow-up and risk of complications in patients with type 2 diabetes (T2DM) followed up for 9 years at a tertiary diabetes center in India. We compared glycemic burden [cumulative time spent above a HbA1c of 53 mmol/mol (7 %)] and incidence of diabetes complications (retinopathy, neuropathy, nephropathy, peripheral arterial disease, coronary heart disease) between 1,783 T2DM patients with "regular follow-up" (minimum of three visits and two HbA1c tests every year from 2003 to 2012), and 1,798 patients with "irregular follow-up" (two visits or less and one HbA1c or less per year during the same time period), retrospectively identified from medical records. Cox proportional hazards models were used to estimate risk associated with diabetes complications. Compared to those with regular follow-up, the irregular follow-up group had significantly higher mean fasting and postprandial plasma glucose, HbA1c, glycemic burden, total and LDL cholesterol, and triglycerides at every time point during the 9 years of follow-up. Those with irregular follow-up had double the total and mean monthly glycemic burden and 1.98 times higher risk of retinopathy (95 % CI 1.62, 2.42) and 2.11 times higher risk of nephropathy (95 % CI 1.73, 2.58) compared to those with regular follow-up, even after adjusting for time-varying confounding variables. Complications tended to develop significantly earlier and were more severe in those with irregular follow-up. Among patients with type 2 diabetes, regular follow-up was associated with significantly lower glycemic burden and lower incidence of retinopathy and nephropathy over a 9-year period.