Paradoxical Relationships Between Anthropometric Variables and Phenotypic Expression of the Metabolic Syndrome in Nondiabetic Polynesians of New Caledonia

Abstract

In the multiethnic population of New Caledonia, the CALDIA (CALedonia DIAbetes Mellitus) Study showed that the prevalence of type 2 diabetes was much higher (15.3%) in Polynesians (mostly Wallisians) than in Melanesians or Europeans (8.4%) (1). Polynesians also exhibit high rates of obesity (2,3), known to be a risk factor for insulin resistance and type 2 diabetes (4,5). However, recent analyses of the CALDIA Study showed that despite high indexes of abdominal obesity, Polynesians had low fasting plasma insulin levels and homeostasis model assessment of insulin resistance (HOMA-IR) (6). Since abdominal obesity is usually associated with impaired fasting glucose, dyslipidemia, and/or hypertension, forming the metabolic syndrome (7,8), we investigated whether these features were present in this group, in comparison with Melanesians and Europeans. The CALDIA Study is a large population-based study of diabetes prevalence in New Caledonia. The protocol has been previously described in detail (1). A population-based sample of 9,390 subjects, aged 30–59 years, residing in New Caledonia >10 years were visited at home for capillary blood glucose measurement. Among them, 643 subjects were known to have diabetes or had capillary blood glucose values ≥6.1 mmol/l when fasting or ≥7.8 mmol/l when not fasting (positive screenees). A total of 588 subjects (response rate 91.5%), together with 517 negative screenees matched …