Survival Rates and Mortality Risk Factors of Thai Patients with Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a common public health problem due to both its micro- and macro-vascular chronic complications. Data on survival rates and mortality risk factors of T2DM in Thailand need to be investigated and updated.

To assess the survival rate and mortality risk factors in T2DM patients.

This study is a part of the Thai DMS Diabetes Complications project which is a prospective observational 4-year study of Thai T2DM patients. All patients were recruited from out-patient departments of seven public hospitals and received standard treatment from their doctors. Their clinical and laboratory status were evaluated annually over 4 years, with particular emphasis on diabetic nephropathy, retinopathy and neuropathy. Outcomes at the end of the four-year study were expressed as survival or death, and causes of mortality were identified.

1,097 from 1,120 stable T2DM patients were enrolled. After 4 years of follow-up, 80 patients (7.3%) had died. Causes of death were: cardiovascular disease (20 cases, 25.0%); infection (20 cases, 25.0%); malignancy (10 cases, 12.5%); end-stage renal disease (4 cases, 5.0%); and other causes (26 cases, 32.5%). Survival rates at 1, 2, 3, and 4 years were 98.9, 97.5, 96.2 and 92.7% respectively. Hazard ratios (95% CI) of all-cause mortality were being over 60 years old 1.84 (1.15-2.94) and having diabetic nephropathy 1.75 (1.12-2.75). Survival rates from cardiovascular mortality at 1, 2, 3, and 4 years were 99.2, 98.4, 97.4 and 94.5% respectively. Hazard ratios (95% CI) of cardiovascular mortality were: female gender 1.75 (1.05-2.94); diabetic nephropathy 1.72 (1.03-2.88); and diabetic retinopathy 1.74 (1.02-2.94).

The survival rate of Thai patients with T2DM over the 4 years was 92.7%. Being over 60 years old and having diabetic nephropathy were associated with all-cause mortality. Female gender, diabetic nephropathy and diabetic retinopathy were associated with cardiovascular mortality.