CHRONIC DIABETIC COMPLICATIONS IN PATIENTS WITH MODY3 DIABETES

MODY3 diabetes, which is caused by a mutation in the hepatocyte nuclea r factor-let gene (HNF-1 alpha) on chromosome 12, represents a relativ ely common monogenic form of diabetes in Finland. Age at onset of the disease can vary from 10 to 60 years, but little is known about the na tural course of the disease, particularly the development of diabetes- related chronic complications. The availability of genetic markers now allows description of the clinical course of the disease. In order to examine the prevalence of chronic diabetic complications in MODY3, we examined 57 carriers with HNF-1 alpha mutations for the presence of m icro-and macrovascular complications. Thirty-four percent of the MODY patients had mild and 13 % had severe non-proliferative or proliferati ve retinopathy; this figure did not differ from the figures in insulin -dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM) patients matched for duration and glycaemic control but not for age. Neither did the prevalence of microalbuminuria differ between MODY3 and IDDM or NIDDM patients (19 vs 24 and 23 %). Neuropa thy was observed with the same frequency as previously reported in IDD M. Hypertension was less frequent in MODY3 and IDDM than in NIDDM (24. 5 and 19 vs 53.7%; p < 0.001). Coronary heart disease was more common in MODY3 than in IDDM (16 vs 4.5 %; p < 0.02) but less common than in the older NIDDM, patients (33.3 %; p < 0.02). In a multiple logistic r egression analysis, poor glycaemic control was an independent risk fac tor for retinopathy (p = 0.03), microalbuminuria (p < 0.04) and neurop athy (p = 0.03). In conclusion, microangiopathic complications are obs erved with the same frequency in patients with MODY3 diabetes as in ID DM and NIDDM and are strongly related to poor glycaemic control.