Newly Diagnosed Type 2 Diabetic Population in Belgium

We read with interest the article by Hillier and Pedula (1). The authors stated that, so far, no study has evaluated baseline metabolic profiles in a newly diagnosed type 2 diabetic population. However, in Belgium a few years ago, a registration of newly diagnosed people with type 2 diabetes was performed in a network of ∼130 sentinel general practices throughout the country. Due to lack of inscription lists by the family physician in our liberal health care system, the free choice of physician within primary, secondary, and tertiary health care and the dissemination of parts of the medical file over the various health care providers that resulted, it was not easy to collect basic population data about sickness and health. Therefore, this method of registration by volunteering family physicians is the only validated (2,3) method to gather at least some epidemiological primary care figures in Belgium.

Data of 651 patients were registered in two consecutive years, 1997 and 1998. After diagnosis of a new patient with type 2 diabetes, the participating family physician ticked a weekly registration form and sent it postfree to the scientific institute for inclusion. Two weeks later, the registering physician received a follow-up questionnaire about the method of diagnosis (1), different patient characteristics (biochemical parameters, diabetes risk factors, and possible early complications) (2), and the management suggested by the physician (treatment initiated for diabetes and possible associated pathology, referral to other health care workers, or possible hospitalization) (3).

The results of this study (4) were submitted for publication. It seems very interesting to compare at least some remarkable similarities despite the different study designs.

A total of 608 individuals met the inclusion criteria: 48 (7.9%) were “early onset” (<45 years of age), and 560 (92.1%) were “usual onset” (≥45 years of age). In comparison with the study of Hillier and Pedula (1), both Belgian onset groups were less obese, but the average BMI was significantly higher for early type 2 diabetes than for usual diabetes (Table 1). An inverse linear relation (Fig. 1) could not be found, possibly because of the small numbers in the early-onset groups. Average BMI varied from 28.6 kg/m² in the 66- to 71-year age group to 33.3 kg/m² in the 41- to 45-year age group. In the oldest age group, the average BMI was 29.6 kg/m². In both onset groups, the prevalence of hypertension at the time of diagnosis was less in the Belgian diabetic population as compared with the American population. The differences between the early- and usual-onset groups were also significant in Belgium.

In our database, there were more women in the early-onset group (56.3%) compared with the usual-onset group (42.1%). HbA_1c was inclined to be higher in the early-onset group, but the difference was not significant; the same results were found for total cholesterol and serum triglycerides.

Despite the disadvantages of our health care system to perform high-quality preventive medicine, Belgian diabetic subjects have a lower risk profile than American diabetic subjects, perhaps resulting from a healthier lifestyle and an earlier time of diagnosis.

We also have data regarding the medical management immediately after diagnosis. No differences can be mentioned between the early- and usual-onset groups. Nearly all newly diagnosed diabetic patients receive food advice from their family physicians. However, not many family doctors actively refer their patients to a dietitian. A recent study in Flanders (Gent and Antwerp) revealed that only 4% of family doctors systematically refer all their patients to the dietitian, whereas 7% never do so. Important pressure points for optimal collaboration are lack of clearly defined tasks on the one hand and lack of refunding for dietary advice on the other (5). Although obesity is more frequent in the early-onset group, we found no differences in the prescription rate for metformin, the first choice for obese diabetic patients (6). We also found that young people with type 2 diabetes are significantly more referred to the diabetologist at the time of diagnosis than older patients.

The representativeness of both the sentinel physicians and sentinel population, with respect to the whole population, remains an important pressure point in this kind of epidemiological analysis. Although the registering physicians are representative of the whole Belgian population of physicians for age and sex, it is not possible to extrapolate the medical practice of family doctors in Belgium. Due to the voluntary nature of participation in the network, random selection of the participants is impossible because the physicians with the greatest motivation answer the call. Registration is done by the physician himself based on his medical file; therefore, the results could be presented rather euphemistically because the data on the follow-up questionnaire probably come closer to the expected guideline level rather than the actual data in the medical record. However, the voluntary nature of the registration and the anonymity of the registering physicians reduce this possible bias. So far, we consider that extrapolation from the sentinel population to the total population is possible.