Data collection and assays

The data was collected through standardized health examinations in a specially equipped examination center. The details of the subjects’ medical history were collected from questionnaires. The anthropometric measurements were taken, including height, weight, circumferences of waist, hips, thigh (just below the buttock fold) using the SECA 201 tape (SECA, Hamburg, Germany) with participants wearing light clothing without shoes. Measurements were performed in accordance with the World Health Organization (WHO) guidelines¹⁴. The waist-to-hip ratio (WHR) was calculated as the ratio of the circumference between the waist and hips. Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared.

The body composition was measured by dual energy X-ray absorptiometry (DEXA) (GE Healthcare, Chicago, Illinois, USA). The gynoid (G) fat (GF) and lean (GL), android (A) fat (AF) and lean (AL), legs (L) fat (LF) and lean (LL) were measured automatically as described previously¹⁵. Fat mass index (FMI), lean mass index (LMI) and Visceral Mass Index (VMI) were calculated as fat, lean and visceral mass in kilograms divided by height in meters squared. The AF/GF ratio was calculated between the fat of the android and fat of the gynoid regions. The GF/total fat (GF/TF) ratio was calculated as ratio between the gynoid fat and total fat. The AF/total fat (AF/TF) ratio was calculated as ratio between the android fat and total fat. The leg fat/total fat (LF/TF) ratio was calculated as ratio between the leg fat and total fat. The ratio of lean GL/total lean (GL/TL), AL/total lean (AL/TL) and legs lean/total lean (LL/TL) were calculated analogously.

The Satisfaction with Life Scale (SWLS)¹⁶ has been used to measure a life satisfaction component of subjective well-being. The scale is a 5-item questionnaire rated on a 7-point scale from 1—strongly disagree to 7—strongly agree. The possible range of scores is 5–35, with a score of 20 representing a neutral point on the scale. Scores between 5 and 9 indicate that a respondent is extremely dissatisfied with life, whereas scores between 31 and 35 indicate that a respondent is extremely satisfied.

Euro Quality of Life Visual Analogue Scale (EQ-5D) was designed to measure health related quality of life³. Visual Analogue Scale (EQ-VAS) is the second part of the questionnaire, asking patients to mark health status on the day of the interview on a 20 cm vertical scale with end points of 0 and 100. The bottom rate (0) corresponds to “the worst health you can imagine”, and the highest rate (100) corresponds to “the best health you can imagine”. This information can be used as a quantitative measure of health outcome as judged by individual respondents.

Depression symptoms were assessed by the Beck Depression Inventory⁴ (BDI), a self-report measurement to assess severity of depression. The scale comprises of 21 questions with four answer options for each question. Each answer recorded scored on a scale of 0 to 3. Higher total scores indicate more severe depressive symptoms.