The relationship between anthropometric indexes of adiposity and vascular function in the FATE cohort

The Association Between Testosterone and Vascular Function in Reproductive-Aged Females With Chronic Kidney Disease

Cardiovascular disease is the leading cause of death in women, and women with chronic kidney disease (CKD) experience especially elevated risk. This study examined the association between testosterone and vascular function in 61 reproductive-aged females with CKD. Testosterone levels and measures of vascular function were assessed, including pulse wave velocity, aortic augmentation, flow-mediated dilation (FMD), and velocity time integral. Multivariable linear regression analyses assessed the relationship between testosterone and each measure of vascular function. No associations were observed between testosterone and vascular function outcomes, although a significant positive association between testosterone-to-estradiol ratio and FMD was demonstrated. Although testosterone levels were not independently predictive of vascular function, the level of testosterone relative to estradiol was associated with FMD and may therefore influence endothelial function in the high-risk population of reproductive-aged female patients with CKD.

Anthropometric measurements and their association with endothelial function and arterial stiffness of eutrophic individuals and with overweight

Objective

The objective of the study was to assess the association of anthropometric measurements with endothelial function and arterial stiffness of eutrophic individuals and with overweight.

Subjects and methods

A cross-sectional study was carried out with individuals with body mass index (BMI) between 18.5 kg/m2 and < 30 kg/m2, low to intermediate global cardiovascular risk scores, and aged ≥ 18 and < 60 years. We assessed the sociodemographic data, anthropometric variables (body weight, height, circumferences of the waist [WC], neck [NC], hip [HC], sagittal abdominal diameter [SAD], [BMI], waist-to-hip ratio [WHR], and waist-to-height ratio [WHtR]), biochemical parameters (lipid profile and nitric oxide), endothelial function (flow-mediated dilation [FMD], by ultrasound), and arterial stiffness (pulse wave velocity [PWV] and the amplification index [AIx@75] by oscillometry). Thirty-six individuals were included, 18 eutrophic and 18 with overweight, with a mean age of 37.5 ± 10.2 years, mostly at low cardiovascular risk (86.1%), female (80.6%), single (52.8%), employed with formal contracts (44.4%), and with over twelve years of education (88.9%).

Results

The PWV presented positive and moderate correlation with the WC (r = 0.584; P = 0.001), WHR (r = 0.513; P = 0.001), and WHtR (r = 0.590; P = 0.001), and positive and low correlation with the NC (r = 0.372; P = 0.013) and SAD (r = 0.356; P = 0.033). Moreover, no anthropometric parameter presented a correlation with the AIx@75 or the FMD percentage in the total sample.

Conclusion

Our findings show that in eutrophic individuals and with overweight the WC, WHR, WHtR, SAD, and NC were positively correlated with the PWV but not to the endothelial function in the overall sample. These are hypothesis-generating findings and they should be replicated in other studies.

Semaglutide improves cardiometabolic risk factors in adults with overweight or obesity: STEP 1 and 4 exploratory analyses

AIMS

Evaluate the effects of once-weekly subcutaneous semaglutide 2.4 mg on cardiometabolic risk factors in people with overweight/obesity without diabetes in the STEP 1 and 4 trials.

MATERIALS AND METHODS

STEP 1 and 4 were phase III, 68-week, placebo-controlled trials of once-weekly semaglutide 2.4 mg combined with lifestyle intervention; STEP 4 had a 20-week semaglutide run-in and 48-week randomized withdrawal period. Participants had a body mass index ≥30 kg/m2 or ≥27 kg/m2 with one or more weight-related comorbidity, without diabetes. Pre-specified endpoints were changes in waist circumference, systolic/diastolic blood pressure (SBP/DBP), lipids, fasting plasma glucose (FPG), fasting serum insulin and antihypertensive/lipid-lowering medication use. Post-hoc assessments included non-high-density lipoprotein (HDL) cholesterol, homeostatic model assessment of insulin resistance (HOMA-IR; STEP 1 only), atherosclerotic cardiovascular disease (ASCVD) risk (American College of Cardiology/American Heart Association algorithm; STEP 1 only) and cardiometabolic risk factors by weight loss achieved (<5%, 5% to <10%, 10% to <15%, or ≥15%) (STEP 1 only).

RESULTS

Of the 1961 participants in STEP 1 and 803 in STEP 4, most had one or more complication/comorbidity at baseline, with dyslipidaemia and hypertension most prevalent. In STEP 1, reductions in waist circumference, SBP, DBP, FPG, fasting serum insulin, lipids and HOMA-IR were greater with semaglutide versus placebo (p ≤ .001). Reductions in SBP, non-HDL cholesterol, low-density lipoprotein cholesterol and FPG were generally greater with semaglutide than placebo within weight-loss categories. Non-significant ASCVD risk reductions were observed with semaglutide versus placebo (p > .05). In STEP 4, improvements in waist circumference, SBP, FPG, fasting serum insulin and lipids during the semaglutide run-in (week 0-20) were maintained over week 20-68 with continued semaglutide, but deteriorated following the switch to placebo (p < .001 [week 20-68]). Net reductions in antihypertensive/lipid-lowering medication use occurred with semaglutide versus placebo (both trials).

CONCLUSIONS

Semaglutide may improve cardiometabolic risk factors and reduce antihypertensive/lipid-lowering medication use versus placebo in adults with overweight/obesity without diabetes. These potential benefits were not maintained after treatment discontinuation.

CLINICALTRIALS

GOV NUMBERS

STEP 1 NCT03548935, STEP 4 NCT03548987.

The Metabolic Profiles of Metabolically Healthy Obese and Metabolically Unhealthy Obese South African Adults over 10 Years

Obesity is associated with an increased cardiometabolic risk, but some individuals maintain metabolically healthy obesity (MHO). The aims were to follow a cohort of black South African adults over a period of 10 years to determine the proportion of the group that maintained MHO over 10 years, and to compare the metabolic profiles of the metabolically healthy and metabolically unhealthy groups after the follow-up period. The participants were South African men (n = 275) and women (n = 642) from the North West province. The prevalence of obesity and the metabolic syndrome increased significantly. About half of the metabolically healthy obese (MHO) adults maintained MHO over 10 years, while 46% of the women and 43% of men became metabolically unhealthy overweight/obese (MUO) at the end of the study. The metabolic profiles of these MHO adults were similar to those of the metabolically healthy normal weight (MHNW) group in terms of most metabolic syndrome criteria, but they were more insulin resistant; their CRP, fibrinogen, and PAI-1act were higher and HDL-cholesterol was lower than the MHNW group. Although the metabolic profiles of the MUO group were less favourable than those of their counterparts, MHO is a transient state and is associated with increased cardiometabolic risk.

Anti-Müllerian hormone and vascular dysfunction in women with chronic kidney disease

Young women with chronic kidney disease (CKD) have disproportionately increased risk of cardiovascular mortality. Reduced anti-Müllerian hormone (AMH) is linked to poor cardiovascular outcomes in the general population, but whether AMH is associated with increased cardiovascular risk in the high-risk CKD population is unknown. This study examined the association between AMH and vascular function, validated markers of cardiovascular risk, in women with CKD. An exploratory cross-sectional study was performed in 47 young women with CKD. Laboratory measurements of AMH were collected. Using standardized protocols, endothelial function was measured with brachial artery flow-mediated dilation and hyperemic velocity time integral. Arterial stiffness was measured with aortic augmentation index and pulse wave velocity. Multivariate linear regression analyses were utilized to evaluate the association between AMH levels and each measure of vascular health. Forty women (36 ± 7 years) with non-dialysis-dependent CKD and 7 women (38 ± 6 years) with dialysis-dependent CKD participated. AMH levels were inversely associated with age (p = 0.01) but not associated with eGFR (p = 0.59) or dialysis status (p = 0.97). AMH was associated with brachial artery flow-mediated dilation (R2  = 0.21 [p = 0.03]) and aortic augmentation index (R2  = 0.20 [p = 0.04]) in the non-dialysis-dependent participants, and with aortic augmentation index in all participants (R2  = 0.18 [p = 0.03]). No association between AMH and any measure of vascular function was demonstrated in the dialysis-dependent participants. AMH levels are associated with impaired vascular function in young women with CKD and may be an important marker of future cardiovascular risk. Further investigation into this female-specific cardiovascular risk factor is warranted in this high-risk population.

Development of muscle mass and body fat reference curves for white male UK firefighters

OBJECTIVE

This study describes the development of the world's first suite of firefighter body composition centile reference curves which can be used as both academic research tools and clinical references, to plot and track individual firefighter skeletal muscle mass (SMM) and fat mass (FM) measurements against the representative reference sample.

METHODS

The body composition of 497 white male London (England) firefighters was measured by anthropometry and bioelectrical impedance analysis. Smoothed centile curves were then generated for skeletal muscle mass index (SMMI), fat mass index (FMI), body fat percentage (BF%) and waist-to-height ratio (WHtR).

RESULTS

Between 48 and 62 years, firefighter SMMI is greater than the UK white male age-matched general population by a mean of 0.35 units, although SMMI declines 0.006 units/years faster in firefighters between these ages. This is estimated to translate to a mean decline of approximately 0.6% of absolute SMM per year. Between 40 and 49 years, firefighter FMI is 0.1 units greater than the UK white male age-matched general population, which becomes identical (7 units) between 50 and 54 years. At the 50th centile, WHtR exceeds 0.5 by 39 years reaching 0.55 at 62 years. This contrasts with FMI which remains stable from 47 years.

CONCLUSION

Firefighters in this study possess greater FM and SMM compared with the UK general population. SMM appears to decline rapidly within older age ranges. These references offer a novel improvement upon the limitations of BMI and BF% for the benefit of an occupational group at elevated risk of cardiovascular disease.

Lifestyle factors associated with the transition from healthy to unhealthy adiposity among black South African adults over 10 years

BACKGROUND AND AIMS

Obesity is associated with an increasing prevalence of cardiovascular diseases in Africa, but some obese individuals maintain cardiometabolic health. The aims were to track metabolically healthy overweight or obesity (MHO) over 10 years in African adults and to identify factors associated with a transition to metabolically unhealthy overweight or obesity (MUO).

METHODS AND RESULTS

The participants were the South African cohort of the international Prospective Urban and Rural Epidemiological study. From the baseline data of 1937 adults, 649 women and 274 men were followed for 10 years. The combined overweight and obesity prevalence of men (19.2%-23.8%, p = .02) and women (58%-64.7%, p < .001), and the prevalence of the metabolic syndrome in all participants (25.4%-40.2%, p < .001) increased significantly. More than a quarter (26.2%) of the women and 10.9% of men were MHO at baseline, 11.4% of women and 5.1% of men maintained MHO over 10 years, while similar proportions (12.3% of women, 4.7% of men) transitioned to MUO. Female sex, age, and total fat intake were positively associated with a transition to MUO over 10 years, while physical activity was negatively associated with the transition. HIV positive participants were more likely to be MHO at follow-up than their HIV negative counterparts.

CONCLUSIONS

One in two black adults with BMI ≥25 kg/m² maintained MHO over 10 years, while a similar proportion transitioned into MUO. Interventions should focus on lower fat intakes and higher physical activity to prevent the transition to MUO.

Adverse effects of long-term weight gain on microvascular endothelial function

BACKGROUND

Endothelial dysfunction is the first stage of the atherosclerotic cascade, and independently associated with cardiovascular events. We evaluated the associations of longitudinal changes in weight, waist circumference, body fat percentage and lean mass index with changes in endothelial function.

METHODS

521 community-based subjects who belonged to hypertensive sibships and had no history of myocardial infarction or stroke had their anthropometric measures and endothelial function assessed a mean of 8.5 years apart. Endothelial function was assessed with brachial artery ultrasound, yielding measures of flow-mediated dilation and reactive hyperemia. We used multivariable linear regression with generalised estimating equations to assess the associations of longitudinal changes (Δ) in anthropometric measures with Δ flow-mediated dilation and reactive hyperemia, adjusting for potential confounders.

RESULTS

Mean±standard deviation age was 57.6±8.7years, 58% were women, and 72% were hypertensive. Most (84%) were overweight or obese at baseline. At end of follow-up, flow-mediated dilation and reactive hyperemia increased by 1.9±7.6% and 51.2±605.8% on average, respectively. In multivariable linear regression, changes in anthropometric measures were not associated with changes in flow-mediated dilation. However, Δ weight (β±SE: -9.00±2.35), Δ waist circumference (-6.78±2.21) and Δ body fat percentage (-19.72±5.62, P<0.0001 for each) were inversely associated with Δ reactive hyperemia. Δ lean mass index was not associated with Δ reactive hyperemia.

CONCLUSIONS

Long-term increases in weight, waist circumference and body fat percentage are associated with progressive worsening of microvascular endothelial function, but not conduit vessel endothelial function, in subjects without a history of cardiovascular events, independently of risk factors.

Blood pressure predicts endothelial function and the effects of ethinyl estradiol exposure in young women

Hypertension, obesity, and endothelial function predict cardiovascular disease in women, and these factors are interrelated. We hypothesized that hypertension and obesity are associated with endothelial dysfunction in young women and that short-term ethinyl estradiol exposure mitigates this dysfunction. We examined flow-mediated dilation (FMD) responses before and during 7 days of oral ethinyl estradiol (30 µg/day) in 19 women (25 ± 5, 18-35 yr). We divided our sample into two groups based on two criteria: blood pressure and obesity. Women were divided into normal blood pressure (NBP; mean arterial pressure range: 78-91 mmHg, n = 7) and high blood pressure (HBP; mean arterial pressure range: 95-113 mmHg, n = 9) groups. We also stratified our subjects by body composition (lean: 18-31%, n = 8; obese: 38-59%, n = 9). We evaluated brachial FMD after two distinct shear stress stimuli: occlusion alone and occlusion with ischemic handgrip exercise. Obesity was unrelated to both FMD responses. Before ethinyl estradiol administration, the HBP group had blunted ischemic exercise responses relative to the NBP group (8.0 ± 3.5 vs. 12.3 ± 3.2%, respectively, P = 0.05). However, during ethinyl estradiol administration, ischemic exercise responses increased in the HBP group (12.8 ± 6.1%, P = 0.04) but decreased in the NBP group (5.6 ± 2.4%, P = 0.01). Standard FMD did not reveal differences between groups. In summary, 1) moderate HBP predicted endothelial impairment, 2) ethinyl estradiol administration had divergent effects on FMD in women with NBP versus HBP, and 3) enhanced FMD (ischemic handgrip exercise) revealed differences in endothelial function, whereas standard FMD (occlusion alone) did not. NEW & NOTEWORTHY We are the first to show that mild hypertension is a stronger predictor of endothelial dysfunction than obesity in healthy women without overt cardiovascular dysfunction. Importantly, the standard 5-min flow-mediated vasodilation stimulus did not detect endothelial dysfunction in our healthy population; only an enhanced ischemic handgrip exercise shear stress stimulus detected endothelial impairment. Estradiol administration increased flow-mediated dilation in women with high blood pressure, so it may be a therapeutic intervention to improve endothelial function.

Adiposity, but not Obesity, Is Associated With Arterial Stiffness in Young Nulliparous Women

Subclinical vascular dysfunction is increasingly recognized as an independent risk factor for cardiovascular events and adverse pregnancy outcomes. The evidence linking indices of obesity and vascular dysfunction is mixed. As an example, some data suggest that adiposity may be a better predictor of endothelial dysfunction than body mass index (BMI). The aim of the current study is to compare the association of obesity, as evaluated by BMI, and a direct measure of body fat to biophysical parameters of vascular function including flow-mediated vasodilation and pulse wave velocity (PWV) in healthy nulliparous reproductive-age women. This is a secondary analysis of data collected as a prospective study of prepregnancy physiology in healthy, nulliparous women. Body mass index was calculated as weight (kg)/height (m²). Total and android body fat were calculated by dual-energy X-ray absorptiometry. Brachial PWV and flow-mediated vasodilation were assessed ultrasonographically. Seventy-nine women were evaluated. Mean BMI was 24.4 (5.4) kg/m², and 15% of women were obese (BMI ≥ 30 kg/m²). In contrast, 39% were considered to have excess adiposity, with ≥39% android body fat. Brachial PWV was associated with increased adiposity, but not obesity. We found no differences in flow-mediated dilation associated with either BMI or body fat. Adiposity may be superior to BMI in identifying women with vascular dysfunction at increased risk of adverse pregnancy outcome and cardiovascular disease. Proper identification may allow implementation of prevention strategies to improve perinatal outcomes and maternal health.

Obesity, arterial function and arterial structure - a systematic review and meta-analysis

OBJECTIVE

Obesity is an established risk factor for cardiovascular disease. The mechanisms by which obesity affects cardiovascular risk have not been fully elucidated. This paper reports a comprehensive systematic review and meta-analysis on obesity and two key aspects of vascular health using gold-standard non-invasive measures - arterial endothelial function (brachial flow-mediated dilatation) and subclinical atherosclerosis (carotid intima-media thickness).

METHODS

Electronic searches for 'Obesity and flow-mediated dilatation' and 'Obesity and intima-media thickness' were performed using Ovid Medline and Embase databases. A meta-analysis was undertaken for brachial flow-mediated dilatation and carotid intima-media thickness to obtain pooled estimates for adults with obesity and those with healthy weight.

RESULTS

Of the 5,810 articles retrieved, 19 studies on flow-mediated dilatation and 19 studies on intima-media thickness were included. Meta-analysis demonstrated that obesity was associated with lower flow-mediated dilatation (-1.92 % [95% CI -2.92, -0.92], P = 0.0002) and greater carotid intima-media thickness (0.07 mm [95% CI 0.05, 0.08], P < 0.0001).

CONCLUSIONS

Obesity is associated with poorer arterial endothelial function and increased subclinical atherosclerosis, consistent with these aspects of vascular health at least partially contributing to the increased risk of cardiovascular events in adults with obesity. These estimated effect sizes will enable vascular health benefits in response to weight loss treatment to be put in greater perspective, both in the research setting and potentially also clinical practice.

Effect of gender and adiposity on in vivo vascular function in young African Americans

The relationship between obesity and high blood pressure is not as strong among African Americans (AA) as compared to Caucasians. We designed the current study to determine the effect of adiposity on vascular endothelial function (a harbinger of hypertension) among young healthy AA without additional cardiovascular disease risk factors. A total of 108 AA subjects (46 women) between the ages of 18 and 45 years were recruited. All the subjects were normotensive, nonsmokers, and normoglycemic. Anthropometric and cardiovascular disease risk factor measurements (lipid, insulin resistance, and inflammatory markers) were obtained. Vascular endothelial function was measured by brachial artery flow-mediated dilation (FMD). Adiposity distribution was measured by using magnetic resonance imaging scan. There were no gender differences in age and levels of blood pressure, lipids, insulin resistance, and inflammatory markers. Women had higher total body fat percentage and higher peripheral adiposity compared to men. We observed that total and central adiposity did not correlate significantly with brachial artery FMD in women (r = -0.12 and r = 0.23, respectively; P = NS). However, in men, waist circumference was positively associated with FMD (r = 0.3, P ≤ .05). Hyperemic flow was negatively correlated significantly with total and central adiposity in men (r = -0.34 and r = -0.48, respectively; P < .05), but not in women (r = -0.26 and r = 0.03, respectively; P = NS). Our study suggests that increased adiposity may pose greater risk to AA men compared to AA women by adversely affecting resistance vessel function (as measured by hyperemic flow). Larger studies are necessary to validate these findings.

Comparison of estimates of body fat content in childhood-onset systemic lupus erythematosus

Objective We aimed to compare estimates of body fat content with respect to their ability to predict the percentage of body fat, confirmed by dual-energy X-ray absorptiometry scans in childhood-onset systemic lupus erythematosus. Methods We included 64 consecutive childhood-onset systemic lupus erythematosus patients and 64 healthy age and sex-matched controls in a cross-sectional study. Anthropometric data, body mass index and body adiposity index were calculated for all subjects. Childhood-onset systemic lupus erythematosus patients were further assessed for clinical and laboratory childhood-onset systemic lupus erythematosus manifestations and fat mass, lean mass and percentage of body fat evaluated by dual-energy X-ray absorptiometry. Results Elevated waist/hip ratio was observed in childhood-onset systemic lupus erythematosus patients when compared to controls ( p < 0.001). We did not find differences between body mass index and body adiposity index classification in childhood-onset systemic lupus erythematosus patients and controls. Using dual-energy X-ray absorptiometry as gold standard we observed that all indirect estimates of body fat were correlated with whole body fat mass. We observed a correlation between height and cumulative corticosteroid dose adjusted by weight ( r = 0.429, p = 0.005) in childhood-onset systemic lupus erythematosus. On whole body analysis we observed a correlation between lean mass and ACR Damage Index scores ( r = -0.395; p = 0.019); percentage of body fat and adjusted Systemic Lupus Erythematosus Disease Activity Index ( r = 0.402; p = 0.008), disease duration ( r = -0.370; p = 0.012). On trunk analysis we observed a correlation between lean mass and ACR Damage Index ( r = -0.319; p = 0.042); percentage of body fat with adjusted Systemic Lupus Erythematosus Disease Activity Index ( r = 0.402; p = 0.005), disease duration ( r = -0.408; p = 0.005). Conclusions This is the first study analyzing body adiposity index in childhood-onset systemic lupus erythematosus patients. We observed that all indirect estimates of body fat were correlated with whole body fat mass. This study shows that we should not replace body mass index by body adiposity index to evaluating fat levels in childhood-onset systemic lupus erythematosus. In consideration of the importance of overweight classification in cardiovascular diseases, any direct estimates of body fat can be used in an attempt to improve the prognosis of patients. Note We believe that we have presented evidence of body adiposity index accuracy in childhood-onset systemic lupus erythematosus patients but further research on the generalizability of body adiposity index to other patient groups needs to be done.

The validity of the body adiposity index in predicting percentage body fat and cardiovascular risk factors among Chinese

OBJECTIVE

Recent research has suggested that body adiposity index (BAI) correlates more closely with percentage body fat (PBF) than body mass index (BMI). Here, we aimed to evaluate BAI's predictive power for PBF and for obesity-associated risk factors in the Chinese population.

SUBJECTS

A total of 1707 women and 680 men aged 51-77 years were analysed in this community-based cross-sectional study.

MEASUREMENTS

Body weight, height, waist circumference (WC) and hip circumference (HC) were measured, and BMI and BAI were calculated. Percentage body fat was determined by dual-energy X-ray absorptiometry (DXA). Blood pressure, fasting lipid profiles, glucose and Carotid ultrasound examination determined intima-media thickness (IMT) at the common carotid arteries (CCA) were also measured.

RESULTS

The Pearson correlation analysis indicated a stronger correlation between BAI and PBF when women and men were pooled together, but this effect disappeared in sex-stratified analysis. Bland-Altman plots suggested that BAI underestimated 5·8% of PBF in women and slightly overestimated 0·28% of PBF in men, but the magnitudes of these biases showed a fat mass-dependent manner. Both the logistic regression and the receiver operating characteristic curve (ROC) analysis indicated that BAI has an inferior predictive power for the presence of hypertension, dyslipidaemia, metabolic syndrome and CCA-intima-media thickening, compared with BMI and WC.

CONCLUSION

We concluded that BAI was neither a better predictor for PBF nor for cardiovascular risks in Chinese population compared with BMI and WC.

Body adiposity index and incident hypertension: the Aerobics Center Longitudinal Study

BACKGROUND AND AIM

The body adiposity index (BAI) has been recently proposed as a new method to estimate the percentage of body fat. The association between BAI and hypertension risk has not been investigated yet. The aim of our study was to evaluate the ability of BAI to predict hypertension in males and females compared with traditional body adiposity measures.

METHODS AND RESULTS

The present follow-up analysis comprised 10,309 individuals (2259 females) free of hypertension from the Aerobics Center Longitudinal Study, who completed a baseline examination between 1988 and 2003. Body adiposity measures included BAI, body mass index (BMI), waist circumference, hip circumference, percentage of body fat and waist to hip ratio (WHR). Incident hypertension was ascertained from responses to mail-back surveys between 1990 and 2004. During an average of 9.1 years of follow-up, 872 subjects (107 females) became hypertensive. Hazard ratios (HRs) and 95% confidence intervals (95% CI) showed that males in the highest categories of all body adiposity measures showed a higher incident risk of hypertension (HRs ranged from 1.37 to 2.09). Females showed a higher incident risk of hypertension only in the highest categories of BAI, BMI and WHR (HRs ranged from 1.84 to 3.36).

CONCLUSION

Our results suggest that in order to predict incident hypertension BAI could be considered as an alternative to traditional body adiposity measures.

Central adiposity and subclinical cardiovascular disease in police officers

Given the associations between obesity and cardiovascular disease (CVD), we evaluated a related but less well-established association between waist circumference and brachial artery reactivity (BAR), a functional measurement of subclinical CVD, where lower levels indicate dysfunction. Regression models examined trends in mean BAR across waist circumference tertiles in police officers, a high-stress occupational group with increased risk for CVD. Mean BAR decreased across increasing waist tertiles among men, but not women, and this association was stronger among officers who consumed more alcohol. Larger waist circumference may be associated with lower BAR, providing an opportunity for intervention prior to disease development.

Cardiovascular reactivity, stress, and physical activity

Psychological stress has been proposed as a major contributor to the progression of cardiovascular disease (CVD). Acute mental stress can activate the sympathetic-adrenal-medullary (SAM) axis, eliciting the release of catecholamines (NE and EPI) resulting in the elevation of heart rate (HR) and blood pressure (BP). Combined stress (psychological and physical) can exacerbate these cardiovascular responses, which may partially contribute to the elevated risk of CVD and increased proportionate mortality risks experienced by some occupations (e.g., firefighting and law enforcement). Studies have supported the benefits of physical activity on physiological and psychological health, including the cardiovascular response to acute stress. Aerobically trained individuals exhibit lower sympathetic nervous system (e.g., HR) reactivity and enhanced cardiovascular efficiency (e.g., lower vascular reactivity and decreased recovery time) in response to physical and/or psychological stress. In addition, resistance training has been demonstrated to attenuate cardiovascular responses and improve mental health. This review will examine stress-induced cardiovascular reactivity and plausible explanations for how exercise training and physical fitness (aerobic and resistance exercise) can attenuate cardiovascular responses to stress. This enhanced functionality may facilitate a reduction in the incidence of stroke and myocardial infarction. Finally, this review will also address the interaction of obesity and physical activity on cardiovascular reactivity and CVD.

Body adiposity index and all-cause and cardiovascular disease mortality in men

OBJECTIVE

To evaluate the association of body adiposity index (BAI) with all-cause and cardiovascular disease (CVD) mortality risk.

DESIGN AND METHODS

The current analysis comprised 19,756 adult men who enrolled in the Aerobics Centre Longitudinal Study and completed a baseline examination during 1988-2002. All-cause and CVD mortality was registered till December 31, 2003.

RESULTS

During an average follow-up of 8.3 years (163,844 man-years), 353 deaths occurred (101 CVD deaths). Age- and examination year-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for all-cause mortality risk were higher for men with high values of BMI (HR = 1.63, 95% CI = 1.19-2.23), waist circumference (1.55, 1.22-1.96), and percentage of body fat (%BF) (1.36, 1.04-1.31), but not for men with high values of BAI (1.28, 0.98-1.66). The HRs for CVD mortality risks were higher for men with high values in all adiposity measures (HRs ranged from 1.73 to 2.06). Most of these associations, however, became nonsignificant after adjusting for multiple confounders including cardiorespiratory fitness.

CONCLUSION

BAI is not a better predictor of all-cause and CVD mortality risk than BMI, waist circumference, or %BF.

Raised BMI cut-off for overweight in Greenland Inuit--a review

Background

Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population.

Objective

This led us to reconsider the cut-off point for overweight among Inuit in Greenland.

Design and findings

We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time.

Conclusion

Defining overweight according to the WHO cut-off of a BMI above 25 kg/m² in Greenland Inuit may overestimate the number of individuals with elevated BMI.