Conference Coverage

Obesity paradox may exist in hypertensive patients with diabetes



AMSTERDAM – A study of Japanese patients with hypertension and glucose intolerance showed that as their body mass index increased, their risk of cardiovascular disease decreased, suggesting the existence of the obesity paradox in this particular population of patients.

However, these findings results don’t refute the fact that severe obesity is a risk factor for cardiovascular disease, and that "hypertensive patients with glucose intolerance and a high BMI [body mass index] should lose weight and restore their BMI to normal range," Dr. Takanori Nagahiro said at the annual congress of the European Society of Cardiology.

Furthermore, the results should be interpreted with caution, because the insulin therapy was higher among patients at the lowest BMI category, indicating that the severity of diabetes may have been different in that group, said Dr. Nagahiro of Nagoya (Japan) University.

The study was a subanalysis of the NAGOYA HEART (Novel Antihypertensive Goal of Hypertension With Diabetes – Hypertensive Events and ARB Treatment) study, which compared the effects of an angiotensin II receptor blocker with a calcium channel blocker on cardiovascular outcomes in 1,150 hypertensive patients with type 2 diabetes or impaired glucose tolerance. No significant differences were found between the two classes. The median follow-up was 3.2 years (Hypertension 2012;59:580-6).

For the current analysis, patients were divided into quartiles according to their body mass indices: Patients in quartile 1 (Q1) had BMIs lower than 23.5 kg/m2 (283 patients); those in Q2 had a BMI range of 23.5-25 (290); those in Q3 had a range of 25-27.5 (277); and patients in Q4 had BMIs higher than 27.5 (255).

The primary outcome in the subanalysis, as in the main study, was a composite of acute myocardial infarction, stroke, admission for heart failure, coronary revascularization, or sudden cardiac death.

There were no significant differences between the four groups, except for age and insulin therapy, where the lowest BMI group had the highest rate of insulin therapy (11%, compared with 6.2%, 4.7%, and 4.7% in Q2, Q3, and Q4, respectively.)

Forty-two (15%; 4.6/100 person-years) patients reached the primary endpoint in Q1, which was used as reference. In Q2, 24 patients (8.3%; 2.3) reached the primary endpoint; and in Q3, 27 patients (9.7%; 2.8) reached the endpoint, both nonsignificant differences. In Q4, however, 13 patients (5.1%; 1.5) reached the endpoint, a significant difference from Q1.

"I think the picture is quite clear now, that metabolic disorders are more important than obesity per se especially if you measure it by body mass index," said Dr. Heinz Drexel, chairman of the department of medicine and cardiology and of the VIVIT Institute, Academic Teaching Hospital Feldkirch, Austria, who cochaired the session at ESC. "I think that’s the bottom line."

The NAGOYA HEART study was funded by Nagoya University, which has received unrestricted research grants from several companies, including Astellas, Bayer, Pfizer, Sanofi-Aventis, and Takeda. Dr. Drexel had no disclosures.

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