Is there an independent association between waist-to-hip ratio and cardiovascular risk factors in overweight and obese women?

The association between lunch composition and obesity in Iranian adults

We aimed to assess the dietary composition of lunch meal using a posteriori-derived dietary patterns and to determine the association of lunch composition with obesity in a sample of Iranian adults. This cross-sectional study was conducted on 850 men and women in Tehran (aged 20-59 years). Dietary intakes were assessed using three 24-h dietary recalls, and dietary patterns were identified via principal component factor analysis. For each identified pattern, scores were calculated for each participant and then classified into tertiles. Central obesity was defined WHO criteria. General obesity was defined as a BMI of more than 30 kg/m2. Three major dietary patterns were identified at lunch meal using twelve food groups: 'Bread, grains and fat', 'Western' and 'Potato and eggs'. After adjustment for potential confounders, participants at the top tertile of the 'Bread, grains and fat' dietary pattern had greater odds for a higher waist-to-hip ratio (WHR), compared with those in the lowest tertile (OR: 1·44, 95 % CI 1·01, 2·07). However, we found no association between 'Western' or 'potato and eggs' patterns and WHR (OR: 0·89, 95 % CI 0·62, 1·28 and OR: 1·16, 95 % CI 0·69, 1·42, respectively). None of the identified dietary patterns was associated when defining obesity with waist circumference or BMI. In conclusion, participants had a greater chance of central obesity defined based on WHR following a lunchtime pattern with a higher and positive loading factor for 'Bread, grains and fat'.

High waist-to-hip ratio levels are associated with insulin resistance markers in normal-weight women

AIM

To assess the association between high waist-to-hip ratio (WHR) levels and insulin resistance (IR) or hyperinsulinemia after oral glucose tolerance test (OGTT) in a sample of normal-weight women.

METHODS

We conducted an analytical cross-sectional study in euthyroid non-diabetic women, who attended the outpatient service of a private clinic in Lima-Peru from 2012 to 2016. Participants were divided in two groups according to the presence or absence of high WHR levels, IR or hyperinsulinemia after OGTT. We considered WHR values > 0.85 as high levels. IR was defined as a Homeostasis Model Assessment (HOMA-IR) value > 2.39 and hyperinsulinemia after OGTT as a serum insulin value ≥ 80μU/mL after 120 min of 75-g glucose intake. We elaborated crude and adjusted Poisson generalized linear models to evaluate the association between high WHR levels and IR or hyperinsulinemia after OGTT and reported the prevalence ratio (PR) with their respective 95% confidence intervals (95%CI).

RESULTS

We analyzed the data of 248 euthyroid, non-diabetic and normal-weight women. The prevalence of high WHR levels was 68.9% (n = 171) while the prevalence of IR and hyperinsulinemia after OGTT was 25% (n = 62) and 15.3% (n = 38), respectively. WHR values were positively correlated with HOMA-IR (r = 0.307; p < 0.001) and serum insulin after OGTT (r = 0.260; p < 0.001). In the adjusted model, high WHR levels were associated with both IR (aPR = 2.63; 95%CI: 1.39-5.01) and hyperinsulinemia after OGTT (aPR = 2.35; 95%CI: 1.03-5.38).

CONCLUSION

High WHR levels were associated with both IR markers used in our study, appearing to be a useful anthropometric indicator to assess IR in euthyroid normal-weight women without type 2 diabetes mellitus.

Relative Importance of Central and Peripheral Adiposities on Cardiometabolic Variables in Females: A Japanese Population-Based Study

In epidemiological studies, there is little evidence regarding the relative impact of central adiposity and peripheral adiposity on cardiometabolic risk factors, especially in Asian populations. This study investigated associations between central-to-peripheral fat ratios and cardiometabolic variables using data from a population-based study of Japanese women. The source population was composed of 1800 women aged 50 yr or older at the 15th- to 16th-yr follow-up survey of the Japanese Population-Based Osteoporosis Cohort Study. This study analyzed cross-sectional data from 998 women for whom complete information about body fat variables according to dual-energy X-ray absorptiometry, cardiometabolic variables, and potential confounding factors was available. Both before and after adjusting for potential confounding factors, trunk-to-appendicular fat ratios showed significant (p < 0.05) correlations with brachial-ankle pulse wave velocity, serum lipids, and hemoglobin A1c levels. Relationships between fat ratios and cardiometabolic variables were independent of relationships between fat volumes (in whole body or in trunk) and cardiometabolic variables. Furthermore, relationships between trunk-to-appendicular fat ratios and cardiometabolic variables were observed among women in the lowest tertile of total body fat (brachial-ankle pulse wave velocity, β = 0.08; high-density lipoprotein cholesterol, β = -0.32; low-density lipoprotein cholesterol, β = 0.15; and hemoglobin A1C, β = 0.16; p < 0.05, respectively). Central adiposity is more related to cardiometabolic variables than peripheral adiposity. Information on central-to-peripheral fat ratios is particularly valuable for the evaluation of relatively thin Japanese women.

Epicardial Fat Thickness is Increased in Vitamin D Deficient Premenopausal Women and does not Decrease after Short-term Replacement

AIM

Vitamin D deficiency, which is prevalent among young women in Middle Eastern populations, has been linked to cardiovascular disease. Epicardial adipose tissue (EAT) has also been found to be associated with coronary artery disease. However, data on the relationship between vitamin D status and epicardial adiposity is limited. This study aims to investigate the effect of vitamin D deficiency and replacement therapy on EAT thickness in healthy, young premenopausal women.

METHODS

Thirty-one premenopausal women with vitamin D deficiency and 31 age-matched women with normal vitamin D levels were enrolled in this study. EAT thickness was measured echocardiographically. Measurements were performed at baseline in both groups and were repeated at the 6-month follow-up in vitamin D deficient subjects after vitamin D replacement therapy.

RESULTS

The baseline plasma 25-hydroxyvitamin D levels were lower in the vitamin D deficient group compared to the control group and were significantly improved following replacement therapy. EAT thickness was significantly higher in the vitamin D deficient group, and no significant change occurred following replacement therapy. In the linear regression analysis, waist circumference (β=0.031 [0.005-0.057], p=0.020) and 25(OH)D level (β=－0.020 [(－0.028)－(－0.013)], p＜0.001) independently correlated with EAT thickness.

CONCLUSION

Vitamin D deficiency is associated with a significant increase in EAT thickness in premenopausal women; however, a net beneficial response to adequate replacement therapy was not observed during the short period of therapy during our study. Longer periods of replacement therapy and follow-up may be useful to demonstrate the potential beneficial effects of vitamin D replacement on epicardial adiposity.

Changes in body fat distribution through menopause increase blood pressure independently of total body fat in middle-aged women: the Korean National Health and Nutrition Examination Survey 2007-2010

Blood pressure in women increases sharply in middle age, especially after menopause. As the menopausal transition is known to induce changes in body fat distribution, the aim of this study was to investigate the effect of body fat distribution as compared with the effect of total body fat on blood pressure through the menopausal transition. We analyzed 1422 subjects aged 45-55 years using the database from the Korean National Health and Nutrition Examination Survey 2007-2010. The waist circumference (WC) of post-menopausal women was larger than that of pre-menopausal women (80.44 cm, 95% confidence interval (CI) 79.36-81.52 vs. 78.94 cm, 95% CI 78.27-79.61, P=0.013), but there was no statistically significant difference in body mass index (BMI). Systolic and diastolic blood pressure (SBP and DBP) were significantly higher in post-menopausal women than in pre-menopausal women: SBP was 118.33 mm Hg, 95% CI 116.52-120.15 vs. 115.22 mm Hg, 95% CI 114.17-116.28 (P=0.003) and DBP was 76.94 mm Hg, 95% CI 75.88-77.99 vs. 75.25 mm Hg, 95% CI 74.57-75.93 (P=0.009). BMI and WC were positively correlated with BP. After adjustment for BMI, the correlation of WC with SBP remained significant (β=0.250, 95% CI 0.024-0.476, P=0.030). In a stratified analysis, WC correlated with SBP in women with BMI<25 kg m(-2) (β=0.358, 95% CI 0.138-0.579, P=0.001), but not in women with BMI25 kg m(-2). We conclude that the changes in body fat distribution through the menopausal transition are associated with SBP, independent of total body fat. This finding indicates that alterations in the localization of body fat are another cause of menopause-related changes in BP.

Centrally located body fat is related to inflammatory markers in healthy postmenopausal women

OBJECTIVE

C-reactive protein and fibrinogen are established atherosclerotic cardiovascular disease risk factors. These acute-phase proteins and the proinflammatory cytokines tumor necrosis factor alpha, interleukin-6, and interleukin-1beta may be elevated in obesity and with menopause. The purpose of this multicenter study was to identify whether centrally located fat and/or overall adiposity were related to these inflammatory markers in healthy postmenopausal women.

DESIGN

We used dual-energy x-ray absorptiometry to assess overall and regional body composition (fat mass in particular) in 242 postmenopausal women in relation to plasma fibrinogen, serum C-reactive protein, and these proinflammatory cytokines.

RESULTS

Multiple regression analyses revealed that 36% of the variability in C-reactive protein (F = 32.4, P <or= 0.0001) was accounted for by androidal fat mass (16.1%, P <or= 0.0001), white blood cells (5.6%, P <or= 0.0001), and age (2.3%, P = 0.0045). Regression analyses revealed that 30% of the variability in fibrinogen (F = 24.5, P <or= 0.0001) was accounted for by white blood cells (3.1%, P = 0.0015), hip fat mass (2.2%, P = 0.0081), years since menopause (0.9%, P = 0.082), and geographic site (P <or= 0.0001). Our results indicated that androidal fat mass and hip fat mass contributed to C-reactive protein and fibrinogen, respectively, whereas we found no association between whole-body or regional fat measures and cytokines.

CONCLUSION

Further study is warranted to determine the responsiveness of these acute-phase proteins and cytokines to loss of body fat through exercise and dietary intervention in postmenopausal women.

Relationship of glycaemic index with cardiovascular risk factors: analysis of the National Diet and Nutrition Survey for people aged 65 and older

Objective

To identify associations between dietary glycaemic index (GI) and weight, body mass index and other risk factors for cardiovascular disease (CVD) – waist-to-hip ratio (WHR), lipoprotein fractions, triacylglycerols (TAG) and blood pressure (BP) – in an older British population.

Design

Cross-sectional dietary, anthropometric and biochemical data from the National Diet and Nutritional Survey for adults aged over 65 years were reanalysed using a hierarchical regression model. Associations between body weight, CVD risk factors, and dietary factors including GI and fibre intakes were explored among 1152 healthy older people living in the UK between 1994 and 1995.

Results

In the unadjusted model, GI was significantly and directly associated with TAG (β = 0.008 ± 0.003) and diastolic BP (β = 0.325 ± 0.164) in males. These relationships were attenuated and non-significant after adjustment for potential confounding factors. WHR (β = 0.003 ± 0.001) and TAG (β = 0.005 ± 0.002) were significantly predicted by GI in males and females combined. The association with WHR was attenuated by adjustment for sex, age, region and social class; the relationship with TAG was non-significant after adjustment for other potential dietary confounders.

Conclusion

After controlling for potential confounders, no clear links were detected between GI and body weight or other CVD risk factors. This study provides little evidence for advising the consumption of a low-GI diet in the elderly to prevent weight gain or improve other CVD risk factors.

Dietary and non-dietary determinants of central adiposity among Tehrani women

OBJECTIVE

To determine the correlates of central adiposity.

DESIGN

Population-based cross-sectional study.

SUBJECTS

A total of 926 women (aged 40-60 years) from all districts of Tehran.

METHODS

Demographic data were collected and anthropometric indices were measured according to standard protocols. Dietary intakes were assessed by means of a semi-quantitative food-frequency questionnaire. The suggested cut-off point for waist-to-hip ratio (WHR>or=0.84) for Tehrani people, adjusted for their age group, was used to determine central adiposity. Logistic regression analysis was used to determine the correlates of WHR, which were adjusted for age, taking medications and body mass index (BMI). The components of dietary intake were determined by factor analysis. Pearson correlation was used to determine the association between the dietary components and WHR. Analysis of covariance was employed to compare the mean values of WHR in different lifestyle groups, with adjustment for BMI and age.

RESULTS

Mean WHR was 0.82 +/- 0.06. The possibility of being centrally obese was higher in women with light physical activity (odds ratio: 2.11; 95% confidence interval: 1.40-2.53), depressed women (1.36; 1.02-1.93), smokers (1.21; 1.02-1.56) and unemployed women (1.41; 1.13-1.72). Marriage (1.31; 1.10-1.82), menopause (1.22; 1.02-1.61), low vitamin C intake (2.31; 1.25-4.25) and low calcium intake (1.30; 1.07-3.78) were associated with central fat accumulation. Dairy consumption was inversely correlated with central fat accumulation (r = -0.2, P < 0.05).

CONCLUSION

Central adiposity is associated with poor lifestyle factors including low physical activity, depression, smoking, low intake of vitamin C, low intake of calcium and dairy products and high fat consumption. Thus lifestyle modifications should be encouraged to achieve a healthier body shape.

Brain white matter expansion in human obesity and the recovering effect of dieting

CONTEXT AND OBJECTIVE

Obesity is associated with several metabolic abnormalities. Recent studies suggest that obesity also affects brain function and is a risk factor for some degenerative brain diseases. The objective of this study was to examine the effects of weight gain and weight loss on brain gray and white matter structure. We hypothesized that possible differences seen in the brains of obese subjects would disappear or diminish after an intensive dieting period.

METHODS

In part I of the study, we scanned with magnetic resonance imaging 16 lean (mean body mass index, 22 kg/m(2)) and 30 obese (mean body mass index, 33 kg/m(2)) healthy subjects. In part II, 16 obese subjects continued with a very low-calorie diet for 6 wk, after which they were scanned again. Regional brain white and gray matter volumes were calculated using voxel-based morphometry.

RESULTS

White matter volumes were greater in obese subjects, compared with lean subjects in several basal brain regions, and obese individuals showed a positive correlation between white matter volume in basal brain structures and waist to hip ratio. The detected white matter expansion was partially reversed by dieting. Regional gray matter volumes did not differ significantly in obese and lean subjects, and dieting did not affect gray matter.

CONCLUSIONS

The precise mechanism for the discovered white matter changes remains unclear, but the present study demonstrates that obesity and dieting are associated with opposite changes in brain structure. It is not excluded that white matter expansion in obesity has a role in the neuropathogenesis of degenerative brain diseases.

Relationship of epicardial adipose tissue with atrial dimensions and diastolic function in morbidly obese subjects

Obesity is associated with atrial dilation and diastolic dysfunction although the causative mechanisms are not completely understood. In this study we showed for the first time that increase in epicardial fat thickness is significantly correlated with atria enlargement and impairment in diastolic filling in morbidly obese subjects.

Larger hip circumference independently contributed to reduced metabolic risks in Tehranian adult women

BACKGROUND

It has been suggested that health professionals may discard measurement of hip circumference from public health screening efforts. Before discarding the hip circumference in epidemiological surveys, it is important to consider whether any important information is likely to be lost.

OBJECTIVE

To evaluate the relationship between hip circumference and metabolic risk factors in an urban adult population of Tehranian women.

DESIGN

In this population-based cross-sectional study, a representative sample of 5720 women aged 18-74 years, were included. Demographic data was collected; anthropometric indices and blood pressure were measured according to standard protocol. Hypertension was defined based on Joint National Committee VI (JNC VI). Biochemical analysis was conducted on fasting blood samples. Diabetes was defined as fasting plasma glucose (FPG) > or =126 mg/dl or 2-h plasma glucose (2hPG) > or =200 mg/dl. Lipid disorders and components of metabolic syndrome were considered based on Adult Treatment Panel III (ATP III).

RESULTS

Mean age of women was 39.9+/-14.6 years. Mean body mass index, waist-to-hip ratio, waist and hip circumferences for subjects were 27.1+/-5.1 kg/m2, 0.83+/-0.08, 86.5+/-13.1 cm and 103.5+/-9.8 cm, respectively. Higher hip circumference was associated with lower levels of serum total- and LDL-cholesterol, serum triglyceride, fasting plasma glucose, 2-h plasma glucose, systolic and diastolic blood pressure. Subjects in the top quintile of hip circumference had higher values of serum HDL-cholesterol concentration compared to those in the lower category. After adjustment for potential confounding variables and anthropometric measures associated with higher hip circumference, a significant decreasing trend was observed for odds of having high LDL-cholesterol (odds ratios among quintiles: 1.00, 0.98, 0.97, 0.95, 0.84, respectively, P for trend=0.04), diabetes (1.00, 0.68, 0.58, 0.45, 0.42, P for trend=0.01), hypertension (1.00, 0.96, 0.82, 0.78, 0.70, P for trend 0.02), low serum HDL-cholesterol (1.00, 1.03, 0.86, 0.82, 0.56, P for trend=0.04), elevated blood pressure (1.00, 0.99, 0.82, 0.70, 0.61, P for trend=0.01) and abnormal glucose homeostasis (1.00, 0.69, 0.66, 0.54, 0.48, P for trend=0.01) among hip circumference quintile categories. Individuals in the upper category of hip circumference had lower odds of having hypercholestrolemia (0.86 vs. 1.00) and high serum triglyceride levels (0.74 vs. 1.00) compared to those in the lowest category.

CONCLUSION

Hip circumference is independently and inversely associated with metabolic risk factors. This study underscores the importance of continuing to measure hip circumference in epidemiologic surveys in Tehranian adult women.

Whole-grain intake and the prevalence of hypertriglyceridemic waist phenotype in Tehranian adults

BACKGROUND

Although dietary guidelines recommend increased intake of grain products to prevent chronic diseases, no epidemiologic data associate whole-grain intake with hypertriglyceridemic waist (HW) phenotype.

OBJECTIVE

We aimed to evaluate the relation between whole-grain intakes and the prevalence of HW phenotype in adults in Tehran, Iran.

DESIGN

Whole-grain intake, serum triacylglycerol concentration, and waist circumference (WC) were assessed in a population-based, cross-sectional study of 827 Iranian subjects (357 men and 470 women) aged 18-74 y. HW phenotype was defined as serum triacylglycerol concentrations > or =150 mg/dL and concurrent WC > or = 80 cm (men) and > or =79 cm (women).

RESULTS

Mean (+/-SD) consumption of whole and refined grains was 93 +/- 29 and 201 +/- 57 g/d, respectively. Subjects in the highest quartile of whole-grain intake had a significantly lower prevalence of HW (29%) than did those in the lowest quartile (44%; P < 0.05). Conversely, those in the highest quartile of refined-grain intake had a significantly higher prevalence of HW (45%) than did those in the lowest quartile (27%; P < 0.05). After control for potential confounding factors, a significantly decreasing trend was observed for the risk of HW phenotype across quartiles of whole-grain intake (odds ratios among quartiles: 1.00, 0.95, 0.90, and 0.78, respectively; P for trend = 0.02). Higher consumption of refined grains was associated with better odds of HW phenotype (by quartile: 1.00, 1.38, 1.65, and 2.1; P for trend = 0.01).

CONCLUSION

Whole-grain intake is inversely and refined-grain intake is positively associated with the risk of HW.

Waist-to-hip ratio is a better screening measure for cardiovascular risk factors than other anthropometric indicators in Tehranian adult men

BACKGROUND

It is essential to identify the best anthropometric index in any population to predict chronic disease risk.

OBJECTIVE

To compare the ability of waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHpR) and waist-to-height ratio (WHtR) to predict cardiovascular risk factors in an urban adult population of Tehranian men.

DESIGN

Population-based cross-sectional study.

SUBJECTS

A representative sample of 4,449 men aged 18-74 y, participants of the Tehran Lipid and Glucose Study

METHODS

Demographic data were collected; anthropometric indices and blood pressure were measured according to standard protocol. In the 18-34 y age category, cutoff points for BMI, WHpR, WHtR and WC were 24 kg/m(2), 0.86, 0.47 and 81 cm, respectively. In the 35-54 y age category these cut points were 26 kg/m(2), 0.91, 0.52 and 89 cm, and in the 55-74 y age category 26 kg/m(2), 0.95, 0.54 and 91 cm, respectively. Hypertension was defined based on JNC VI. Biochemical analysis was conducted on fasting blood samples. Diabetes was defined as fasting plasma glucose > or =126 mg/dl or 2hPG > or =200 mg/dl and dyslipidemia based on ATP III. The presence of 'at least one risk factor' from the three major cardiovascular risk factors (hypertension, dyslipidemia and diabetes) was also evaluated.

RESULTS

Mean age of men was 41.8+/-15.4 y. Mean BMI, WHpR, WC and WHtR for subjects were 25.6+/-4.2 kg/m(2), 0.91+/-0.07, 87.7+/-11.7 cm and 0.51+/-0.02, respectively. Dyslipidemia and 'at least one risk factor' are more prevalent risk categories. Although all anthropometric indicators had a significant association to cardiovascular risk factors, WHpR had the highest correlation coefficients compared to other anthropometric measures. For all risk factors in all age categories, the highest odds ratios were pertained to WHpR. Of the four individual indicators, WHpR had the highest sensitivity, specificity and accuracy to predict cardiovascular risk factors. Cutoff points for WHpR were seen to have a higher percentage of correct prediction than BMI, WC and WHtR in all age categories.

CONCLUSION

It is concluded that WHpR is a better predictor for cardiovascular risk factors than BMI, WC and WHtR in Tehranian adult men.