Chlorpropamide-alcohol flushing in non insulin-dependent diabetes: prevalence of small and large vessel disease and or risk factors for angiopathy

Genetic and metabolic risk factors for the development of late complications in type I (insulin-dependent) diabetes

The genetic background seems to be involved in the development of type I diabetes and it might also be involved in the development of diabetic complications, but studies carried out so far have yielded conflicting results. The aim of this study was to evaluate the influence of some genetic markers and metabolic factors in the development of late diabetic complications. One hundred and twenty-seven patients (69 males, 58 females) with type I diabetes were evaluated for ABO and Rh blood groups, chlorpropamide alcohol flush (CPAF) and acetylator phenotype (AP) as well as for life-habits (smoking, alcohol use, diet and drug compliance), metabolic indexes (M-value, HbA1, cholesterol and triglyceride levels) and late complications of diabetes [coronary heart disease (CHD), arterial hypertension (AH), retinopathy and nephropathy]. Diabetic patients were more frequently fast acetylators and CPAF positive than controls and CPAF was more frequent among females than among males. None of the genetic markers used in this study appeared as a risk factor for the development of diabetic complications. At multiple logistic analysis different risk factors appeared for each microangiopathic complication. For retinopathy: female sex, duration of disease and triglyceride levels; for nephropathy: male sex, cholesterol levels and hypertension. These risk factors have already been recognized in previous studies, while the genetic markers evaluated in our study do not identify a greater or smaller risk for the development of late complications.

Association between chlorpropamide-alcohol flushing and fast acetylator phenotype in type I and type II diabetes

Different prevalences of chlorpropamide alcohol flushing (CPAF) have been reported by different authors in either type I or type II diabetics or in normal subjects and this could be due to different methodological approaches or to different criteria of evaluation of CPAF. Previous studies in small series of patients have also suggested the existence of an association between type I diabetes and the fast acetylator phenotype (AP). The first aim of this study was to find reliable criteria for the assessment of CPAF. The second was to evaluate the prevalence of CPAF and of AP in a large series of type I and type II diabetics; and the third was to evaluate possible associations of CPAF and AP. AP and CPAF were evaluated separately in 256 diabetics (110 with type I and 146 with type II diabetes) and in 183 diabetics (74 with type I and 109 with type II diabetes), respectively. In 156 of these subjects, the two markers were evaluated together. The occurrence of CPAF was studied by subjective and objective assessment and by thermographic recording; CPAF was quantified by the differential value of skin temperature increase [delta T(C-P)] and by the value of differential speed of ascent, expressed in angle-degrees [delta a(C-P)], after treatment with placebo and with chlorpropamide. The fast AP was more frequent in type I than in type II diabetics, was not related to family history of diabetes, sex of the patients, age at onset and duration of diabetes or metabolic control. The most reliable assessment of CPAF was represented by thermographic recording of speed of ascent of skin temperature. CPAF was more frequent in females than in males, more frequent in diabetics than in healthy controls, similarly frequent in type I and in type II diabetes and showed no relationship with family history of diabetes, age at onset, duration of diabetes or metabolic control. An association between fast AP and CPAF was found in type II, but not in type I diabetics: fast acetylators were more frequently CPAF-positive, while slow acetylators were more frequently CPAF-negative. In addition, a linear relationship was found between rate of acetylation and speed of ascent of facial skin temperature after chlorpropamide and alcohol in type II diabetics, not in type I diabetics. The meaning of this association is not clear and deserves further investigations.

[Facial vasomotor flushing due to alcohol-chlorpropamide. Prevalence in diabetic and non-diabetic patients]

Using a standard test (sherry 40 ml 12 hours and 36 hours after 250 mg chlorpropamide), chlorpropamide-alcohol flush (CPAF) prevalence was 34 p. 100 (19/56) in non insulin-dependent diabetics (NIDD), 10 p. 100 (3/30) in insulin-dependent diabetics and 7 p. 100 (2/27) in controls. Family history of diabetes was not associated with CPAF trait. Conflicting results in the literature might be explained by bias in patients selection or methodology.