[Prevalence of type II diabetes mellitus in population of Krakow].

UNLABELLED: The study was carried out within a framework of the Polish Multicenter Study on Diabetes Epidemiology in 1998-2000. The aim of the study was to define the prevalence of type 2 diabetes, especially unknown diabetes, and prevalence of impaired glucose tolerance in a demographically well-defined urban population using the comparable epidemiological methods which were applied in the previous study in Wrocław in 1985-1986. The study was carried out in 200,000 subjects inhabiting the town quarter. Out of those who were 35 or more 6000 subjects were randomised using a table of random numbers. All randomized subjects received a letter of invitation explaining the sense of study, its objectives and methods. If necessary the invitations were renewed, and then the subjects were contacted by phone. Each responding person received a questionnaire to complete. Then anthropometric and blood pressure measurements were taken. Blood was sampled for plasma glucose, insulin, total cholesterol, HDL cholesterol and triglycerides in the fasting state. Those who declared being non-diabetic and in whom screening test using a glucometer (Glucotrend) revealed fasting glycemia below 8 mmol/l underwent an oral glucose tolerance test (75 g) to determine glycemia and insulinemia at 120 min. Plasma glucose, total cholesterol, HDL cholesterol and triglycerides concentrations were measured with an enzymatic method, whereas insulinemia was defined with the IRMA technique, using ready kits Swierk-Poland. Diabetes mellitus and impaired glucose tolerance were recognised according to the 1985 WHO criteria. Chi square test, Fisher's test and Mann-Whitney test were used for statistical analysis. Statistical analysis was carried out using the statistical package BMDP. During 3 years of the study out of 6000 randomly selected subjects 3060 (1731 women and 1329 men) responded. In the study population 192 patients were with known diabetes, including 150 subjects receiving oral antidiabetic agents or insulin at the time of the study or some with high fasting glycemia not receiving any treatment except a diet. The 42 subjects who prior to the study had not been receiving hypoglycemic agents or in whom fasting glycemia had been below 8 mmol/l underwent an oral glucose tolerance test. Of them diabetes was confirmed in 11 patients, impaired glucose tolerance was observed in 9, and glucose intolerance was excluded in 22 subjects. Thus, in the study group 161 subjects (75 women and 86 men) with a mean age 61.5 +/- 8.95 years had already diabetes. Their mean BMI was 31.5 +/- 4.6 kg/m2 and did not differ significantly between both sexes. Only HDL cholesterol was significantly higher in men (women 1.1 +/- 0.3 vs. men 1.3 +/- 0.3, p < 0.001) in this group. Among those who declared being non-diabetic 160 subjects (77 men and 83 women), mean age 58.0 +/- 9.7 years and mean BMI 31.4 +/- 4.9 kg/m2 had diabetes identified according to the 1985 WHO criteria. Fasting insulinemia was 16.6 +/- 12.0 uj/ml in this group. At 120 min OGTT insulinemia in women was higher than in men (152.6 +/- 90.5 vs. 112.0 +/- 83.4, p < 0.01). In the whole study population diabetes was found in 321 subjects, including 161 with known and 160 with newly diagnosed diabetes. Based upon these data a standardized prevalence rate due to type 2 diabetes was calculated being 5.37% for the whole population (2.82% for known and 2.55% for unknown diabetes, respectively). When only part of the population over 35 years of age was taken into consideration, the rate was 10.77% (5.66% for known and 5.11% for unknown diabetes). When only fasting glycemia according to ADA recommendation was analysed, diabetes was recognised in 160 subjects (107 men and 53 women). In 78 subjects (49 men and 29 women) diabetes was diagnosed according to the WHO and ADA criteria. When oral glucose tolerance test and glycemia at 120 min exceeding 11.1 mmo/l is considered a gold standard for the diagnosis of diabetes, the diagnostic accuracy of the ADA criteria is 48.7%. In the study population 449 (14.55%) subjects (201 men and 248 women), mean age 56.6 +/- 9.6 years and mean BMI 29.7 +/- 4.6 (men 29.0 +/- 3.7 vs. women 30.2 +/- 5.2, p < 0.01) had impaired glucose tolerance. In our study population there were 572 subjects (329 men and 243 women) with impaired fasting glucose. Of them 359 subjects (212 men and 147 women) had normal glucose tolerance in OGTT, 161 (99 men and 62 women) had impaired glucose tolerance, and 52 (18 men and 62 women) type 2 diabetes. Thus, of the 572 subjects 9% (5.4% of men and 13% of women) had diabetes type 2, and 28% (30% of men and 25% of women) had impaired glucose tolerance. As the frequency of impaired glucose tolerance in this subgroup is higher than in the whole study population it seems justified to identify a group of subjects with increased fasting glycemia and to administer OGTT.

CONCLUSIONS: 1. A significant rise in the prevalence of type 2 diabetes was observed between 1986 and 2000 (from 3.7% to 10.77%). 2. Prevalence of unknown diabetes increased considerably (reaching 5.11%). 3. The similar rise in the prevalence of impaired glucose tolerance was observed between 1986 and 2000 (from 2.9% to 14.5%) 4. Early detection of type 2 diabetes should be based upon oral glucose tolerance test according to the WHO.