Correlation between waist circumference and other factors in menopausal women in Thailand ()
1. INTRODUCTION
Similar to waist circumference (WC), blood pressure (BP), fasting blood glucose (FBG), triglyceride (TG) and HDL cholesterol (HDL-C) is one of the factors used in the diagnosis of metabolic syndrome (MS).Waist circumference measurement is a simple method at no cost while waist hip ratio (WHR) reflects the fat distribution and can predict the MS and other cardiovascular risks. However WHR is more difficult than WC measurement.
Currently MS is more frequently diagnosed because of increasing concern of this problem, the lifestyle change and more aging population. Metabolic syndrome patients carry a higher risk for cardiovascular disease and diabetes mellitus and also for a mortality rate associated with these causes [1,2].
The prevalence of MS is higher when women going through menopausal period [3,4]. However, at the present there is a trend that both men and women of all age group have abnormal cholesterol level and more abdominal obesity [5].
The criteria for diagnosis of MS varies due to the definition (modified National Cholesterol Education Program Adult treatment Panel III: modified NCEP ATP-III or International diabetes federation: IDF criteria) including WC, BP, FBG, TG and HDL-C. Both criteria share the common issues for WC (≥80 cm for Asian women), high BP (BPs ≥ 130 mmHg or BPd ≥ 85 mmHg or on drug treatment ), TG ≥ 150 mg/dL, FBG ≥ 100 mg/dL and HDL-C < 50 mg/dL in women or on drug treatment. Diagnosis of MS by modified NCEP ATP-III requires at least 3 of 5 parameters [6] and by IDF is WC in combination with 2 of 4 parameters [7].
The prevalence of dyslipidemia in Asian is gradually increased including Thai population. In the menopausal transition more dyslipidemia is detected. The previous report of the prevalence of dyslipidemia in Thai menopausal women was very high (TC ≥ 200 mg/dL 91.25%, LDLC ≥ 190 mg/dL 48.75%, TG ≥ 150 mg/dL 10% and HDL –C < 50 mg/dL 38.75% ) [8].
Since WC is a simple method to reflect the central obesity and one of the criteria for diagnosis of MS, many authors recommend its use to predict the risk and give the advice for patients. However, there is a limited number of study in menopausal women concerning the correlation between WC and lipid profile, FBG and BP.
The aim of the present study was to find the correlation between WC, and also WHR, and other metabolic profiles such as lipid profiles, FBG and BP. A positive correlation with these parameters may lead to its use to predict the risk factors for MS. As it is simple with no cost, WC can be applied on a wide scale to promote health in mass population.
2. MATERIALS AND METHODS
All women attending menopause clinic at Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University were recruited. Participants were 400 women with menopausal symptoms age at least 40 years old with no medication for diabetes mellitus, hypertension, dyslipidemia, autoimmune disease and other medical problems. Participants included both non-hormone use (no hormone use before or discontinue hormone for at least 6 months before enrollment, N 200) and hormone use (currently under hormone therapy, N 200). Participants were measured for body weight, height, WC, HC and BP with written inform consent. Waist hip ratio (WHR) and BMI were then calculated.
All anthropometry was measure by trained author (KS) with standard technique. Body weight and height was measure by standard equipment. Waist circumference was measure with plastic tape at midway between the lower costal margin and the iliac crest while women is standing without clothes at this region. Hip circumference was measure at the hip level at the widest part of buttocks without excess clothes. All parameters were then calculated such as BMI, WHR.
Venous blood sample was also taken for FBG and lipid profiles (TG, TC, LDL-C and HDL-C) after 12 hours fasting. Blood was analyzed by the Central Laboratory of the hospital. All assays were performed using automatic machine Unicel DXC 800 Synchrone clinical system, Beckman Couter Inc. Fasting blood glucose levels were assayed using glucose oxidase method, while TC with cholesterol oxidase, esterace, peroxidase method, TG with enzymatic method and LDL-C, HDL-C with direct measure method.
The sample size was calculated base on the prevalence of dyslipidemia in Thai menopausal women. The author predicts the difference not more than 10% and then the sample size was calculated to be 138 women per group (for non hormone and hormone use).Statistic analysis was performed by SPSS version 14.0 program. Descriptive data was presented by mean ± SD or percent. Student t test was used to compare the difference of characteristics between groups. Pearson correlation was performed to test the correlation between WC, WHR, age, BW and BMI with the following parameters such as BP, FBG and lipid profiles. Chi square test was used to test the difference between groups in terms of BP, FBG and lipid profiles.
The present study was approved by the research ethic committee of the Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
3. RESULTS
The characteristics of all participants are presented in Table 1. Mean age of all participants was 53.4 ± 5.8 years. Mean waist and hip circumference were 76.2 ± 8.0 and 95.9 ± 6.7 cm, respectively. Mean BMI was 23.3 ± 3.1 kg/m2. Systolic and diastolic hypertension were found in 36.8% and 17.8% of participants, respectively. The prevalence of hypertriglyceridemia (≥150 mg/dL), hypercholesterolemia (≥200 mg/dL), high LDL-C (≥130 mg/dL) and low HDL-C (<50 mg/dL) were 18.3%,73.3%, 54.8% and 35.0%, respectively. Among participants undergone hormone therapy, mean duration of hormone use was 52.1 ± 47.5 months. Table 2 compares the characteristics of participants classified by WC at cut-off level at 80 cm and by WHR at cut-off level at 0.8. Age and TC were not different between groups classified by WC. While BMI, BP, FBG, TG, LDL-C and HDL-C were significantly different between groups. All parameters were higher in participants with WC ≥ 80 cm except HDL-C was vice versa. Table 2 also demonstrates the characteristics of participants classified by WHR. Age, BP and TC levels were not significant different between groups, while BMI, FBG, TG, LDL-C and HDL-C were significantly different. All parameters, except HDL-C, were higher in the group of WHR ≥ 0.8.
Table 3 represents the Pearson correlation between WC, WHR, age, body weight, BMI with the following parameters such as BP, FBG and lipid profiles. Waist circumference had the positive correlation with BP (both systolic and diastolic), FBG and TG and the negative correlation
Table 1. Characteristics of all participants (Mean ± SD): N 400.
Table 2. Characteristic of participants classified by waist circumference (WC) or waist hip ratio (WHR) (mean ± SD) (student’s t test).
Table 3. The pearson correlation between waist circumference/waist-hip ratio/age/body weight/BMI with the following parameters (blood pressure, fasting blood glucose and lipid profiles).
with HDL-C. This correlation was similar when WHR, BW and BMI were analyzed. Although WC, WHR, BW and BMI had similar correlation with such parameters but the correlation was not strong. Age was the poor indicator because it had a weak correlation with only systolic BP, FBG and HDL-C.
Waist circumference, WHR, age, BW and BMI had the negative correlation with HDL-C.
The Chi square test comparing WC and WHR and such parameters are shown in Table 4. When WC was used (cutoff level at 80 cm), high FBG, high TG, high LDL-C and low HDL-C were found to be significantly higher in large WC compared to small WC. When WHR was used (cutoff level at 0.8), high FBG, high TG and low HDL-C were found significantly more prevalent in large WHR, the same as large WC.
Table 5 compares BP, FBG, TG, TC, LDL-C and HDLC between hormone use and non-hormone use.Both groups were not different un terms of BP, FBG, TG, LDL-C and HDL-C. Total cholesterol was significant higher in nonhormone use.