[The selective detection of glucose intolerance and diabetes in primary care. The ITG-Reus (Tarragona) Study. The Glucose Intolerance Research Group].

Objective: To investigate the number of people with intolerance to glucose (ITG) and undiagnosed diabetes (DM) among primary care users at risk.
Design: Prospective, selective urban polling of a representative sample of those attended in the city of Reus (88,000 inhabitants).
Setting: Two base health areas (10 Primary Care teams) with an approximate overall reference population of 45,000 inhabitants.
Patients and Other Participants: Clinical and examination data were recorded with a pre-designed questionnaire. Diagnoses were established by means of base glycaemia (mmol.l-1 or a 75 g glucose oral overload (0 and 120 minutes) for users over 40 with some Diabetes risk factor. Further tests were HbA1C (%), base peptide-C (nmol.l-1, total cholesterol, HDL cholesterol, triglycerides (mmol.l-1 and 24-hour microalbuminuria (mg).
Measurements and Main Results: After a year included in the survey, the data of 345 people were evaluated: 151 men, 58 years old (95% CI, 57-60) and BMI of 30.8 (30.3-31.4), with 197 diagnoses (57.1%) of normal tolerance to glucose (52-62%). 82 (23.8%) of ITG (20-28%) and 66 (19.1%) of undiagnosed DM (15-23%). Significant differences between the three were detected in age (56/61.5/61.7 years, p < 0.001), proportion of men (38/50/53%, p < 0.05), diagnosis of hypertension (40.6/59.8/53%, p < 0.01), previous anomaly in tolerance 28.4/45.1/51.5%; p < 0.001), HbA1C (4.6/4.9/5.4; p < 0.001), systolic pressure (140.5/143.6/151 mmHg, p < 0.007). Triglycerides (1.4/1.6/2.1, p < 0.001) and microalbuminuria (16/29/51, p < 0.001). Base peptide-C (3.5/3.8/3.8) showed no statistical differences.
Conclusions: Selective detection in primary care amply exceeds opportunist detection in identifying patients with ITG who might be susceptible to preventive measures. In function of the intolerance level, from normality through to DM, statistical differences were found in HbA1C, systolic pressure, Triglyceridaemia and urinary excretion of albumin. These were not extendable to the rest of the lipid profile or to endogenous insulinaemia.