Application of a novel sex independent anthropometric index, termed angle index, in relation to type 2 diabetes: a Trinidadian case-control study

BMJ Open. 2019 Feb 19;9(2):e024029. doi: 10.1136/bmjopen-2018-024029.

Abstract

Objective: To develop a novel sex independent anthropometric index, termed as angle index, related to type 2 diabetes.

Design: Case-control.

Participants: The study comprised 121 participants and were divided into two groups. One group had no form of diabetes and served as controls (n=50). The other group had the condition of type 2 diabetes (n=71). 31% (n=37) of the subjects were male and 69% (n=84) were female. 62% (n=75) of the subjects were of East Indian ethnicity, 28% (n=34) were of African ethnicity and 10% (n=12) were of mixed ethnicity.

Setting: Participants of the study were from the island of Trinidad, located in the Caribbean. Patients in the study were selected at random from hospital records.

Primary outcome measure: It was hypothesised that the mean angle index of patients with type 2 diabetes would be higher than the mean angle index of patients without type 2 diabetes.

Results: Patients with type 2 diabetes had a significantly higher angle index value as compared with controls (p<0.001). Angle index was the superior sex independent anthropometric index in relation to type 2 diabetes (area under the curve=0.72; p<0.001) as compared with other sex independent variables. Angle index correlated with glycated haemoglobin (rs=0.28, p=0.003) and fasting blood glucose (rs=0.31, p=0.001) levels. Patients with type 2 diabetes were four times more likely to have an angle index greater than 184° (OR 4.2, 95% CI 1.8 to 9.9) as compared with controls.

Conclusion: Angle index was a superior sex independent index for discriminating between patients with and without type 2 diabetes, as compared with waist circumference, abdominal volume index, conicity index, blood pressure readings, triglyceride levels and very low-density lipoprotein levels.

Keywords: angle index; anthropometry; obesity; type 2 diabetes; waist.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anthropometry / methods*
  • Asian People
  • Black People
  • Blood Pressure
  • Case-Control Studies
  • Cholesterol, VLDL
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / metabolism*
  • Female
  • Glycated Hemoglobin / metabolism
  • Humans
  • Male
  • Middle Aged
  • Obesity, Abdominal / diagnosis*
  • Obesity, Abdominal / epidemiology
  • Risk Assessment
  • Triglycerides
  • Trinidad and Tobago
  • Umbilicus
  • Waist Circumference
  • Waist-Hip Ratio

Substances

  • Cholesterol, VLDL
  • Glycated Hemoglobin A
  • Triglycerides
  • hemoglobin A1c protein, human