Characterization of type 2 diabetes mellitus in first generation Italian migrants to Belgium

Abstract

Type 2 diabetes mellitus is a major metabolic disease in developed countries, and preferentially affects low-income groups and/or people from Southern extraction. Migrants are especially at risk. In Belgium, a large population of workers emigrated in the 50s and 60s, especially from rural areas of Southern Italy and Sicily. We tested the hypothesis that type 2 diabetes mellitus' phenotype in these Italian migrants could differ from that observed in autochthonous Belgian subjects. We retrospectively compared the clinical files of 485 patients with type 2 diabetes either of Belgian (n=445) or Italian origin (n=40). Italians were younger at diagnosis (46 +/- 14 vs. 52 +/- 13 years, P < 0.01), shorter, had a lower education and a stronger family record of diabetes (89 vs. 47%, P < 0.01). They had similar BMIs (31 +/- 6) and similar or slightly worse degree of sedentarity (>75%). We further compared this Italian group to 115 Belgians subjects matched for age, sex, and education. Known duration of diabetes (16 years), smoking and drinking habits, use of oral hypoglycaemic, antihypertensive and hypolipaemic drugs, complications, CRP, estimated glomerular filtration rate, micro-albuminuria prevalence, blood pressure, insulin sensitivity/ beta-cell function estimated by HOMA modelling, as well as fat mass indirectly estimated by impedancemetry were not significantly different between the two populations. There was a non significant trend toward higher HbAlc (8.7 +/- 2 vs. 8.2 +/- 2%, NS) in Italian subjects whose LDL-cholesterol was however significantly lower (105 +/- 31 vs. 120 +/- 33 mg.dL-1, P < 0.01) as well as folic acid (5 + 1.7 vs. 6.7 +/- 4, P < 0.001). Insulin dose was higher (0.77 +/- 0.4 vs. 0.48 +/- 0.3 IU.day-1, P < 0.001) and abdominal obesity less prevalent in males (33 vs. 58%, P < 0.01) of this group. Thus, Italian diabetic subjects in Belgium exhibit higher insulin requirements despite similar/better BMI, known duration of diabetes, HOMA indices, use of oral antidiabetic drugs, abdominal obesity and slightly higher HbA1c. This points towards different dietary habits, as do the differences in folic acid and LDL-cholesterol; different patterns of exercise may also play a role. Higher family record of diabetes may be genetic, but may also be biased by tighter family structure in subjects of Italian extraction.