Incidence of insulin-dependent diabetes (IDDM) and non-insulin-dependent diabetes (NIDDM) (0-34 years at onset) in Benghazi, Libya

The incidence of insulin-dependent diabetes (IDDM) and non-insulin-dependent diabetes (NIDDM) in Benghazi, Libya in the < 35-year age group during the period 1981-1990 are reported. Incidence data for IDDM were based on prospective registration of patients while incidence data for NIDDM were based on analysis of files. Case ascertainment of IDDM cases was estimated to be > 95%. Incidence of total diabetes (IDDM and NIDDM) (per 100 000 population) was significantly higher in females (43.8; 95% confidence Interval (CI) 40.6-47.2) than in males (28.9, 26.6-31.3) (P < 0.001). The overall incidence rates of IDDM and NIDDM were 9.0 (CI, 8.1-10.0) and 27.3 (CI, 25.4-28.2), respectively. Rates of IDDM were 9.4 (CI, 8.1-10.9) among males and 8.5 (CI, 7.3-10.0) among females. Rates of NIDDM were 19.6 (CI, 18.1-22.2) among males and 35.3 (CI, 32.4-37.8) among females. IDDM patients showed a female predominance in the 0- to 14-year age range (P > 0.05) and a male predominance in the 15- to 34-year age range (P > 0.05). NIDDM showed equal incidence in males and females in the 0- to 14-year age range and twofold higher incidence in females than in males in the 15- to 34-year age group (P < 0.001). Yearly variation and seasonality of onset were not significant in IDDM cases (P > 0.05). Fifty-six percent of NIDDM cases were obese compared to only 6% of IDDM cases. The study revealed that diabetes mellitus is a common chronic disease in children and young Libyan Arabs. It has shown that NIDDM in Benghazi is twofold higher in females than in males in the 15- to 34-year age group. It has also shown that age per se is not a reliable criterion for the classification of diabetes into IDDM and NIDDM.