Objective: To determine the factors predisposing patients with type-2 diabetes mellitus to gallstone disease.
Design: Case-control study.
Place and duration of study: The medical outpatient clinic of the University of Ilorin teaching hospital, Ilorin, Nigeria, from July, 2003 to June, 2004.
Patients and methods: One hundred type 2 diabetic patients and 100 age and gender-matched controls underwent real time ultrasonography to study factors predisposing patients with type 2 diabetes mellitus to gallstone disease. The age, gender, body mass index (BMI), duration of diabetes mellitus and serum lipids were determined in the individuals enrolled for the study.
Results: Fifteen percent of the diabetic patients had ultrasound evidence of gallstone disease as compared to 7% in non-diabetic controls. There was a steady increase in the incidence of gallstone disease in diabetic patients with age with a peak incidence in the seventh decade i.e. 60-69 years, and a decline in the eighth decade i.e. 70 - 79 years. The average age of the diabetic patients with gallstone disease - 59.1+ 9.5 years was significantly higher than in those without gallstone disease - 51.8 + 10.5 years (p = 0.014). The mean duration of disease in the diabetic patients with gallstone disease was 5.0 + 4.9 years compared with 4.5 + 3.8 years in the diabetic patients without gallstone disease (p=0.772). The mean serum cholesterol and triglyceride levels - 4.3 + 1.3 mmol/L and 1.5 + 0.8 mmol/L respectively in the diabetic patients with gallstone disease was higher than in those without gallstone disease - 3.4 + 0.5 mmol/L (p=0.0941) and 1.4 + 0.7 mmol/L (p=0.712) respectively. The mean body mass index for the diabetic patients with gallstone disease was 26.2 + 5.5 kg /m2 compared with 25.7 + 6.7 kg/m2 in those without gallstone disease (p=0.755) .
Conclusion: Increasing age is a risk factor for gallstone disease in diabetic patients. Hyperlipidaemia, female gender, heavier weight and a longer duration of diabetes mellitus appear to be associated risk factors.