Recently, Bulhões and Araújo (1) reported a high prevalence of metabolic syndrome in 102 Brazilian hypertensive patients, especially when using International Diabetes Federation (IDF) criteria for the metabolic syndrome (2). We have some methodological criticisms regarding their study: blood pressure levels were not described; criteria adopted for diagnosis of hypertension were not those recommended by the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (3); and data on waist circumference and HDL were not presented individually for men and women.
Considering that all patients had high blood pressure, besides abnormal waist circumference—an obligatory feature for the IDF diagnosis—only one more component was required to classify patients as belonging to the metabolic syndrome group. Actually, the high prevalence of metabolic syndrome was already expected because patients were selected by the presence of one metabolic syndrome component. This comment is supported by demonstration of a high prevalence of metabolic syndrome when patients were selected by the presence of diabetes, another metabolic syndrome component. In a sample of consecutive 212 type 2 diabetic outpatients (80.8% hypertensive; pressure 142 ± 22/83 ± 11 mmHg), the prevalence of metabolic syndrome (IDF criteria) was 81.3%, similar to that reported by Bulhões and Araújo (82.4%; P = 0.911). The age (60.7 ± 10.5 vs. 60.1 ± 10.3 years; P = 0.635) and BMI (28.7 ± 4.2 vs. 28.6 ± 4.1 kg/m2; P = 0.857) of their and our patients, respectively, were not different. Nevertheless, because the prevalence of metabolic syndrome increases with age (4), this aspect must also be considered.
When we evaluated a sample of 110 hypertensive (3) patients (blood pressure 135 ± 15/87 ± 10 mmHg; BMI = 33.9 ± 4.7 kg/m2) attending the Internal Medicine Outpatient Clinic, a rather low frequency of metabolic syndrome (IDF criteria) of 51.8% was observed. This could be explained by a lower age (44.2 ± 7.6 years) compared with that of the patients in the Bulhões and Araújo study and also compared with that of our type 2 diabetic patients (P < 0.0001 for both comparisons); even the latter were overweight or obese. In conclusion, a high prevalence of metabolic syndrome is predictable when patients are selected by the presence of one metabolic syndrome component, especially in relatively old patients.