Body Adiposity Index Indicates Only Total Adiposity, Not Risk

TO THE EDITOR: Bergman et al. (1) suggested in a recent publication in this journal a new body adiposity index (BAI) calculated from measurements of the hip and height. This index showed a significant correlation with body fat measurement by dual-energy X-ray absorptiometry (1) which could replace the widely used BMI. In addition predicting adiposity, it was not clear if the BAI could recognize patients at risk to metabolic syndrome. To assess whether the BAI could identify patients with different glucose tolerance status, we calculated BAI in patients with normal glycemia, impaired fasting glucose, impaired glucose tolerance, and type 2 diabetes. We also evaluated other adiposity indexes (waist circumference, waist-to-hip ratio, waist-to-height ratio, and BMI). The aim was to demonstrate which of the independent variables best correlated with fasting and 2 hours (2hG) glycemias and systolic blood pressure, and diastolic blood pressure. BAI was the only index that showed no difference among the glucose tolerance different groups (P = 0.26, Table 1) and, compared to other adiposity indexes, it showed the lowest correlation with fasting glycemia (r = 0.16), 2hG (r = 0.13), systolic blood pressure (r = 0.20), and diastolic blood pressure (r = 0.22). Larger series had shown that different adiposity indexes, as determined by anthropometric measurements, had a good relationship with susceptibility to diabetes mellitus and prediabetes. BMI in men and waist circumference in women had the best correlation in some series (2). The use of BMI showed best indication in patients with arterial hypertension (3) and, depending on the population studied, elevated waist-to-hip ratio was the best index to predict metabolic syndrome (4). The poor correlation found in our database could be because the BAI formula calculates the index of adiposity based on hip circumference alone. BAI provides an estimated measurement of total body fat, including the subcutaneous fat. Subcutaneous fat produces more adiponectin (5) and protects against the metabolic syndrome (4). On the other hand, central obesity (waist circumference) seems to be the main focus of the association of anthropometric measures and susceptibility to type 2 diabetes and hypertension (6). Thus, the BAI shown in the article (1) does not seem to be better than the older indexes to predict some diseases as diabetes and hypertension. BAI indicates the total body fat but does not reflect fat distribution. Men and women with the same BAI can easily present with different cardiovascular risks, probably worse in men who usually deposits more visceral fat than women. Reproduction of our data in larger series and evaluation of more variables may clarify the actual role of the BAI in clinical practice. The authors declared no conflict of interest.