Changes in waist circumference and the incidence of acute myocardial infarction in middle-aged men and women

Background

Waist circumference (WC) measured at one point in time is positively associated with the risk of acute myocardial infarction (MI), but the association with changes in WC (DWC) is not clear. We investigated the association between DWC and the risk of MI in middle-aged men and women, and evaluated the influence from concurrent changes in BMI (DBMI).

Methodology/Principal Findings

Data on 38,593 participants from the Danish Diet, Cancer and Health study was analysed. Anthropometry was assessed in 1993–97 and 1999–02. Information on fatal and non-fatal MI was obtained from National Registers. Cases were validated by review of the medical records. Hazard ratios (HR) were calculated from Cox proportional hazard models with individuals considered at risk from 1999–02 until December 30 2009. During 8.4 years of follow-up, 1,041 incident cases of MI occurred. WC was positively associated with the risk of MI, but weakly after adjustment for BMI. DWC was not associated with the risk of MI (HR per 5 cm change  = 1.01 (0.95, 1.09) with adjustment for covariates, baseline WC, BMI and DBMI). Associations with DWC were not notably different in sub-groups stratified according to baseline WC or DBMI, or when individuals with MI occurring within the first years of follow-up were excluded.

Conclusions/Significance

WC was positively associated with the risk of MI in middle-aged men and women, but changes in WC were not. These findings suggest that a reduction in WC may be an insufficient target for prevention of MI in middle-aged men and women.     

BMI and waist circumference as indicators of health among Samoan women

Objective: High rates of obesity and chronic disease make establishment of effective indicators of risk for chronic disease important. The objective was to examine adequacy of anthropometric cut‐off points as indicators of risk for chronic disease among Samoan women in Hawaii. Research Methods and Procedures: A cross‐sectional survey of 55 Samoan women 18 to 28 years of age that included blood lipids, cholesterol, and glucose (including after a 2‐hour oral glucose test); anthropometry (weight, height, waist circumference); and DXA of body composition. Results: Using the Centers for Disease Control and Prevention (CDC)/World Health Organization (WHO) cut‐off points for BMI, 22% of women were overweight and 58% were obese. Cholesterol, lipid, and glucose values were all linearly related to DXA body fat, BMI, and waist circumference. BMI and waist circumference at WHO/NIH cut‐off points predicted levels of blood lipids and glucose that indicate elevated risk for disease. Discussion: WHO/NIH cut‐off points for BMI and waist circumference reflect risk indicators of chronic disease among young Samoan women in Hawaii.     

BMI, waist circumference, and incident urinary incontinence in older women

Overall body fat and central adiposity may reflect different mechanisms leading to urinary incontinence (UI). We examined the associations of BMI and waist circumference with incident UI, including the independent associations of BMI and waist circumference with UI type, among women aged 54-79 years in the Nurses' Health Study. Study participants reported their height in 1976 and their weight and waist circumference in 2000. From 2000 to 2002, we identified 6,790 women with incident UI at least monthly among 35,754 women reporting no UI in 2000. Type of incontinence was determined on questionnaires sent to cases with at least weekly incontinence. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using multiple logistic regression. There were highly significant trends of increasing risk of UI with increasing BMI and waist circumference (P for trend <0.001 for both). Multivariable RRs of developing at least monthly UI were 1.66 (95% CI 1.45-1.91) comparing women with a BMI of > or =35 kg/m(2) to women with BMI 21-22.9 kg/m(2) and 1.72 (95% CI 1.53-1.95) comparing women in extreme quintiles of waist circumference. When BMI and waist circumference were included in models simultaneously, BMI was associated with urge and mixed UI (P for trend 0.003 and 0.03, respectively), but not stress UI (P for trend 0.77). Waist circumference was associated only with stress UI (P for trend <0.001). These results suggest that women who avoid high BMI and waist circumference may have a lower risk of UI development.     

Ethnic-specific BMI and waist circumference thresholds

BMI and waist circumference (WC) are used to identify individuals with elevated obesity-related health risks. The current thresholds were derived largely in populations of European origin. This study determined optimal BMI and WC thresholds for the identification of cardiometabolic risk among white and African-American (AA) adults. The sample included 2096 white women, 1789 AA women, 1948 white men, and 643 AA men aged 18-64 years. Elevated cardiometabolic risk was defined as ≥2 risk factors (blood pressure ≥ 130/85 mm Hg; glucose ≥100 mg/dl; triglycerides ≥150 mg/dl; high-density lipoprotein-cholesterol <40 mg/dl (men) or <50 mg/dl (women)). Receiver Operating Characteristic (ROC) curves were used to identify optimal BMI and WC thresholds in each sex-by-ethnicity group. The optimal BMI thresholds were 30 kg/m2 in white women, 32.9 kg/m2 in AA women, 29.1 kg/m2 white men, and 30.4 kg/m2 in AA men, whereas optimal WC thresholds were 91.9 cm in white women, 96.8 cm in AA women, 99.4 in white men, and 99.1 cm in AA men. The sensitivities at the optimal thresholds ranged from 63.5 to 68.5% for BMI and 68.4 to 71.0% for WC and the specificities ranged from 64.2 to 68.8% for BMI and from 68.5 to 71.0% for WC, respectively. In general, the optimal BMI and WC thresholds approximated currently used thresholds in men and in white women. There are no apparent ethnic differences in men; however, in AA women the optimal BMI and WC values are ~3 kg/m2 and 5 cm higher than in white women.     

Alpha-linolenic acid intake and 10-year incidence of coronary heart disease and stroke in 20,000 middle-aged men and women in the Netherlands

Background

Whether intake of alpha-linolenic acid (ALA), the plant-derived n-3 polyunsaturated fatty acid (PUFA), could prevent cardiovascular diseases is not yet clear. We examined the associations of ALA intake with 10-year incidence of coronary heart disease (CHD) and stroke in the Netherlands.

Methods

Data were collected from a general population of 20,069 generally healthy men and women, aged 20 to 65 years. Habitual diet was assessed at baseline (1993–1997) with a validated 178-item food frequency questionnaire. Incidences of CHD and stroke were assessed through linkage with mortality and morbidity registers. Hazard ratios (HR) were calculated with multivariable Cox proportional hazards models, adjusted for age, gender, lifestyle, and dietary factors.

Results

During 8–13 years of follow-up, we observed 280 incident CHD events (19% fatal) and 221 strokes (4% fatal). Intakes of energy-adjusted ALA in quintiles ranged from less than 1.0 g/d in the bottom quintile (Q1) to more than 1.9 g/d in the top quintile (Q5). ALA intake was not associated with incident CHD, with HRs varying between 0.89 and 1.01 (all p>0.05) in Q2–Q5 compared with the bottom quintile of ALA intake. For incident stroke, however, participants in Q2–Q5 had a 35–50% lower risk compared with the reference group. HRs were 0.65 (0.43–0.97), 0.49 (0.31–0.76), 0.53 (0.34–0.83), and 0.65 (0.41–1.04) for Q2–Q5 respectively.

Conclusion

In this general Dutch population, ALA intake was not associated with incident CHD. The data suggested that a low intake of ALA may be a risk factor for incident stroke. These results warrant confirmation in other population-based studies and in trials.     

Interrelationship of waist circumference and subcutaneous fat with metabolic and blood pressure measures among Asian Indian men

People of South Asian origin (e.g. Indians) usually have a more centralized distribution of body fat with thick trunk skinfolds and markedly higher mean waist circumference (WC) for a given level of body fat percentage compared to Europeans and are exceedingly susceptible to coronary heart disease (CHD) worldwide. Owing to ethnic heterogeneity, population specific information on the interrelationship of fat topography with metabolic and blood pressure measures in different Indian populations is immediately required. In view of the above consideration the present work was undertaken to study the interrelationship of the WC and the sum of four (biceps, triceps, subscapular, suprailiac) skinfolds (SF4) with metabolic and blood pressure variables among the well-off Bengalee men aged 30 years and above from Calcutta and suburbs. The sample of the present study comprises 212 male railway employees of the Eastern Railway, Government of India. All 212 subjects were residents of Calcutta and its suburbs. Anthropometrics, lipids (total cholesterol, fasting triglyceride, high, low and very low density lipoprotein cholesterol), fasting plasma glucose and blood pressure measures were taken from each participant. Two-sample (unpaired) t-test revealed that centrally obese men (waist circumference=90 cm) had significantly greater means compared to centrally non-obese subjects for metabolic risk factors and blood pressure. Inter-tertile comparison of lipids, lipoproteins and glucose revealed that there existed no significant differences in their distribution according to SF4 tertiles. The results of multiple regression analyses (after controlling for the linear, cubic and quadratic effect of age) using waist circumferences and SF4 as independent variables demonstrated the significant effect of central obesity on metabolic and blood pressure variables in the study population. This finding indicated the clinical and physiological importance of central body fat accumulation particularly in and around the waist line in explaining risk factors for chronic diseases, e.g. CHD.     

Similar level of impairment in exercise performance and oxygen uptake kinetics in middle-aged men and women with type 2 diabetes

The present study tested the hypothesis that the magnitude of the type 2 diabetes-induced impairments in peak oxygen uptake (Vo(2)) and Vo(2) kinetics would be greater in females than males in middle-aged participants. Thirty-two individuals with type 2 diabetes (16 male, 16 female), and 32 age- and body mass index (BMI)-matched healthy individuals (16 male, 16 female) were recruited. Initially, the ventilatory threshold (VT) and peak Vo(2) were determined. On a separate day, subjects completed four 6-min bouts of constant-load cycling at 80% VT for the determination of Vo(2) kinetics using standard procedures. Cardiac output (CO) (inert gas rebreathing) was recorded at rest, 30, and 240 s during two additional bouts. Peak Vo(2) (ml·kg(-1)·min(-1)) was significantly reduced in men and women with type 2 diabetes compared with their respective nondiabetic counterparts (men, 27.8 ± 4.4 vs. 31.1 ± 6.2 ml·kg(-1)·min(-1); women, 19.4 ± 4.1 vs. 21.4 ± 2.9 ml·kg(-1)·min(-1)). The time constant (s) of phase 2 (τ(2)) and mean response time (s) of the Vo(2) response (MRT) were slowed in women with type 2 diabetes compared with healthy women (τ(2), 43.3 ± 9.8 vs. 33.6 ± 10.0 s; MRT, 51.7 ± 9.4 vs. 43.5 ± 11.4s) and in men with type 2 diabetes compared with nondiabetic men (τ(2), 43.8 ± 12.0 vs. 35.3 ± 9.5 s; MRT, 57.6 ± 8.3 vs. 47.3 ± 9.3 s). The magnitude of these impairments was not different between males and females. The steady-state CO responses or the dynamic responses of CO were not affected by type 2 diabetes among men or women. The results suggest that the type 2 diabetes-induced impairments in peak Vo(2) and Vo(2) kinetics are not affected by sex in middle aged participants.     

Age at menarche, the leg length to sitting height ratio, and risk of diabetes in middle-aged and elderly Chinese men and women

Aims

To evaluate the associations of age at menarche and the leg length-to-sitting-height ratio, markers of adolescent growth, with risk of diabetes in later life.

Materials and Methods

Information from 69,385 women and 55,311 men, aged 40–74 years from the Shanghai Women''s Health Study and Shanghai Men''s Health Study, were included in the current analyses. Diabetes status was ascertained through biennial in person follow-up. Cox models, with age as the time scale, were used.

Results

There were 2369 cases of diabetes (1831 women; 538 men) during an average of 7.3 and 3.6 years of follow-up of the women and men, respectively. In females, menarche age was inversely associated with diabetes risk after adjustment for birth cohort, education, and income (HR = 0.95, 0.92–0.98). In both genders, leg length-to-sitting-height ratio was inversely related to diabetes (HR = 0.88, 0.80–0.97 for men; HR = 0.91, 0.86–0.96 for women) after adjustment for birth cohort, education, and income. Further adjustment for adult BMI at study enrollment completely eliminated the associations of age at menarche (HR = 0.99, 0.96–1.02) and the leg length-to-sitting-height ratio (HR = 1.00, 0.91–1.10 for men; HR = 1.01, 0.96–1.07 for women) with diabetes risk.

Conclusions

Our study suggests that markers of an early age at peak height velocity, i.e. early menarche age and low leg-length-to-sitting height ratio, may be associated with diabetes risk later in life and this association is likely to be mediated through obesity.     

Increasing trends in waist circumference and abdominal obesity among US adults

Objective: Some studies have shown that abdominal obesity may be a better predictor than overall obesity for disease risks and all‐cause mortality. This study sought to examine the recent trends in waist circumference (WC) among adults in the United States. Research Methods and Procedures: Data from the National Health and Nutrition Examination Survey during 1988–1994, 1999–2000, 2001–2002, and 2003–2004 were analyzed to estimate the trends in the mean WC and the prevalence of abdominal obesity. Pooled t tests were used to test the differences in estimates between two time periods. Results: Between the periods of 1988–1994 and 2003–2004, the age‐adjusted mean WC increased from 96.0 cm to 100.4 cm among men (p < 0.001) and from 89.0 cm to 94.0 cm among women (p < 0.001); the age‐adjusted prevalence of abdominal obesity increased from 29.5% to 42.4% among men (p < 0.001) and from 47.0% to 61.3% among women (p < 0.001). Between the periods of 1999–2000 and 2003–2004, a significant increase occurred in mean WC only among men (from 99.0 cm to 100.4 cm; p = 0.03) and in the prevalence of abdominal obesity among both men (from 37.0% to 42.2%; p = 0.03) and women (from 55.3% to 61.3%; p = 0.04). People with a BMI of 25 to 29 kg/m² had a greater relative increase in abdominal obesity. Discussion: The mean WC and the prevalence of abdominal obesity among U.S. adults have increased continuously during the past 15 years. Over one‐half of U.S. adults had abdominal obesity in the period of 2003–2004.     

Conflicting effects of BMI and waist circumference on iron status

The association between obesity and iron status has a long history and is still receiving attention. However comparative analysis of the association between general obesity (BMI) and visceral obesity (waist circumference) with iron status has not been extensively researched. The aim of the present study is thus to determine if body mass index and waist circumference have the same correlation with iron status. One thousand one hundred and thirty people (225 men and 905 women) aged 30 years and above participated in this study. Anthropometric parameters, haemoglobin, iron and total iron binding capacity concentrations were measured using standard methods. Percentage transferrin saturation was calculated and ferritin concentrations were measured using an enzyme linked immunosorbent assay. Obese or overweight women had significantly lower iron and transferrin saturation concentration when compared to non-obese women. In contrast, women with high waist circumference had comparable plasma iron and transferrin saturation to women with normal waist circumference. Partial correlation analysis and linear regression analysis showed that BMI is negatively and significantly associated with plasma iron, transferrin saturation, Hb and ferritin concentration, whilst waist circumference is positively but insignificantly associated with plasma iron, transferrin saturation, Hb and ferritin concentration. Binary regression analysis showed that obese or overweight people are more likely to have iron deficiency, whilst those with raised waist circumference are more likely to have iron overload. Multivariate analysis showed that body mass index is negatively and significantly associated with low iron status, while waist circumference is positively and insignificantly associated with iron status. This is supported by a comparison of plasma iron, transferrin saturation and ferritin concentrations in participants with high body mass index and normal waist circumference and participants with normal body mass index and high waist circumference to those participants having normal body mass index and normal waist circumference. The present study suggests that in women body mass index is associated with low plasma iron, transferrin saturation and ferritin concentrations, while waist circumference is associated with high plasma iron, transferrin saturation and ferritin concentrations.     

Hypertriglyceridemic waist phenotype is associated with decreased insulin sensitivity and incident diabetes in elderly men

Objective: To investigate the association between hypertriglyceridemic waist (HTGW) and insulin sensitivity (assessed by euglycemic clamp method), and the development of diabetes in a longitudinal community‐based cohort of elderly men without diabetes at baseline. Design and Methods: The present cross‐sectional study comprised 1,026, 70‐year‐old men without diabetes. The gold standard euglycaemic–hyperinsulinaemic clamp technique was used. Six‐year follow‐up on diabetes status were available in n = 667. The HTGW phenotype was defined as having waist circumference ≥ 90 cm, and triglycerides ≥ 2 mmol L^?1. The men were stratified into those having normal WC and TG (n = 299), one HTGW component (n = 606), and HTGW (n = 121). Results: The association between insulin sensitivity and one HTGW component as well as HTGW was highly significant (P < 0.001) in the whole sample, as well as in individuals with high/low BMI (stratified at ≥25). In longitudinal analyses, participants with HTGW was associated with a more than fourfold increased risk for diabetes (Odds ratio 4.64, 95% CI 1.61–13.4, P = 0.004) compared to those with normal WC and TG. Conclusion: The present study both confirm and extend previous research suggesting that the HTGW‐phenotype portrays an increased glucometabolic risk, also in lean individuals.     

Determining the waist circumference in african americans which best predicts insulin resistance

Total body size and central fat distribution are important determinants of insulin resistance. The BMI and waist circumference (WC) thresholds in African Americans that best predict insulin resistance are unknown. Our goal was to determine the BMI and WC values in African Americans, which optimally predict insulin resistance. The subjects were African Americans (68 men, 63 women), aged 35 +/- 8 years (mean +/- s.d.), with a BMI of 30.9 +/- 7.5, in the range of 18.5-54.7 kg/m(2), and with a WC of 98 +/- 18, in the range of 69-173 cm. Insulin resistance was defined by the lowest tertile of the insulin sensitivity index (S(I)). The Youden index was calculated to determine the WC and BMI thresholds that predict insulin resistance with an optimal combination of sensitivity and specificity. In men the thresholds that optimally predicted insulin resistance were a BMI > or =30 kg/m(2) or a WC > or =102 cm. For women, insulin resistance was best predicted by a BMI > or =32 kg/m(2) or a WC > or =98 cm. In African Americans, insulin resistance (in men) was best predicted by a WC > or =102 cm, and in women by a WC > or =98 cm, or by a BMI value that fell in the obese category (men: > or =30 kg/m(2), women: > or =32 kg/m(2)).     

Measurement of waist circumference predicts coronary atherosclerosis beyond plasma adipokines

Objective:

The association of plasma adipokines beyond waist circumference (WC) with coronary artery calcification (CAC), a measure of subclinical atherosclerosis, is unknown.

Design and Methods:

Asymptomatic Caucasian individuals from two community‐based cross‐sectional studies (n = 1,285) were examined and multivariate analysis of traditional risk factors was performed, then WC and adipokines (adiponectin and leptin) were added. Incremental value of each was tested with likelihood ratio testing.

Results:

Beyond traditional risk factors, WC (Tobit regression ratio 1.69, P < 0.001) and plasma leptin (1.57, P < 0.001) but not plasma adiponectin (P = 0.75) were independently associated with CAC. In nested models, neither adiponectin (χ² = 0.76, P = 0.38) nor leptin (χ² = 1.32, P = 0.25) added value to WC beyond traditional risk factors, whereas WC added incremental value to adiponectin (χ² = 28.02, P < 0.0001) and leptin (χ² = 13.58, P = 0.0002).

Conclusion:

In the face of important biomarkers such as plasma adiponectin and leptin, WC remained a significant predictor of CAC beyond traditional risk factors underscoring the importance of WC measurement during cardiovascular risk assessment.     

BMI and waist circumference in predicting cardiovascular risk factor clustering in Chinese adolescents

Objective: To derive the optimal BMI and waist circumference (WC) cut‐off values to predict clustering of cardiovascular risk factors in Hong Kong Chinese adolescents. Research Methods and Procedures: A total of 2102 Hong Kong Chinese 12 to 19 years of age were recruited. Participants were considered to have clustering of risk factors if at least three of the following risk factors were present: 1) high‐density lipoprotein cholesterol (HDL‐C) ≤1.03 mM, 2) low‐density lipoprotein cholesterol (LDL‐C) ≥2.6 mM, 3) triglyceride (TG) ≥1.24 mM, 4) fasting plasma glucose (FPG) ≥6.1 mM, and 5) age‐, sex‐, and height‐adjusted systolic or diastolic blood pressure (BP) ≥ 90th percentile. Receiver operating characteristics (ROC) curves were generated to identify the optimal age‐adjusted BMI and WC cut‐off values to predict clustering of risk factors in boys and girls separately. These age‐adjusted BMI and WC cut‐offs were transformed to percentile values. Cole's lambda‐mu‐sigma (LMS) method was used to obtain smoothed age‐specific BMI and WC at these percentile values. Results: The areas under ROC curves for BMI in girls and boys were 0.85 [95% confidence interval (CI), 0.77 to 0.92] and 0.76 (95% CI, 0.66 to 0.85), respectively. The respective areas under ROC curves for WC in girls and boys were 0.82 (95% CI, 0.74 to 0.91) and 0.78 (95% CI, 0.68 to 0.87). The optimal BMI thresholds were at the 78th percentile for girls and the 72nd percentile for boys. The respective values for WC were at the 77th percentile for girls and the 76th percentile for boys. The sensitivities and specificities of these cut‐off values ranged from 72% to 80%. Discussion: Age‐ and sex‐specific BMI and WC cut‐off values can be used to identify adolescents with clustering of cardiovascular risk factors.