Body adiposity index as a risk factor for the metabolic syndrome in postmenopausal Caucasian, African American, and Filipina women

Abstract

Aims

To investigate the utility of the body adiposity index (BAI) and its association with the metabolic syndrome (MetS) in older Caucasian (n = 369), African American (n = 336) and Filipina (n = 275) women.

Methods

Dual energy X-ray absorptiometry, anthropometric measures, plasma glucose and medical history were assessed in 1993–1999.

Results

Despite smaller body size, 32.7% of Filipina women had higher MetS compared to African American and Caucasian women based on the National Cholesterol Education Program (NCEP) (32.7% vs 19.6% and 13.3%, respectively) or the International Diabetes Federation (IDF) (42.6% vs 33.0% and 18.7%, respectively ps < 0.05). BAI had higher positive correlations with BMI, %body fat (%BF), and %truncal fat in Caucasian than African American and Filipina women. Adjusted for age, smoking, estrogen use, exercise, and alcohol intake, odds of the MetS (NCEP) were 2.08 (95%CI: 1.52–2.85) by BAI, 3.04 (95%CI: 2.11–4.38) by BMI, and 2.13 (95%CI: 1.52–3.00) by %BF for Caucasian women; 0.92 (95%CI: 0.69–1.23) by BAI, 1.44 (95%CI: 1.09–1.90) by BMI, and 1.12 (95%CI: 0.84–1.50) by %BF for African American women; and 1.14 (95%CI: 0.88–1.47) by BAI, 1.51 (95%CI: 1.15–1.97) by BMI, and 0.96 (95%CI: 0.74–1.25) by %BF for Filipinas.

Conclusion

BAI was better able to assess adiposity in postmenopausal Caucasian women compared to African American and Filipina women. This index can distinguish ethnic differences in MetS confirmed by %BF.

Introduction

Obesity or accumulated adiposity is an important etiological factor in the clustering of clinical conditions that comprise the metabolic syndrome (MetS) [1]. These conditions include central obesity, hypertension, hyperglycemia, and dyslipidemia [2], [3]. Having the MetS in turn, predisposes individuals for more serious chronic clinical outcomes, such as cardiovascular disease (CVD), type 2 diabetes, and possibly some cancers [2], [4].

Although, high precision imaging techniques, including computed tomography (CT) or dual-energy X-ray absorptiometry (DXA) imaging, are considered to be the gold standard for measuring fat distribution, their clinical value is often undermined by the cost and time burden associated with CT or DXA. Therefore, other markers including weight, waist circumference, skinfold patterns, BMI and waist–hip ratio are used as convenient and economical clinical proxies to evaluate adiposity [5], [6]. While anthropometric thresholds provide a general assessment of risk, they may not provide a valid basis for comparisons between ethnic groups, and ethnic specific thresholds must be considered [7], [8], [9].

Previous reports have shown the importance of considering ethnic differences in fat distribution when assessing adiposity using BMI [10], [11]. Persons from different ethnic groups with similar BMIs can be at dissimilar risks for poor health outcomes attributable to increased adiposity. For example, several studies suggest that despite similar BMI, Indians, Asians, and Filipina women living in the US have higher visceral adipose tissue compared to Caucasians. while African American women have less visceral adipose tissue despite significantly larger BMI [12], [13]. Also, variations of body fat do not correlate with BMI variations in Mexican American, non-Hispanic White, and non-Hispanic Black adolescents [14].

A recent analysis by Bergman and colleagues, reported that the body adiposity index (BAI) based on hip circumference and height, was highly correlated with DXA measures of body fat in relatively young African American and Mexican American men and women (average age 35 years) [15]. The applicability of this index has been studied in various populations such as middle-aged and elderly Caucasian adults, post-menopausal Caucasian women, multi-ethnic cohorts predominantly Caucasian or African American, and Chinese adults, however the conclusions drawn have been inconsistent [16], [17], [18], [19], [20], [21]. However, there have been no studies comparing BAI and its association with the MetS in older women of Caucasian, African American, and Filipino ethnicities.

The purpose of this study is to examine the association of BAI with other adiposity markers in Caucasian, African American, and Filipina women aged 50–70 years and to investigate the utility of BAI as a risk factor for the MetS in community dwelling women of these ethnicities.