General and abdominal adiposity and risk of death in Europe

Body mass index can similarly predict the presence of multiple cardiovascular risk factors in middle-aged Japanese subjects as waist circumference

OBJECTIVE

Adiposity is closely associated with the clustering of metabolic risk factors such as high blood pressure, dyslipidemia, and glucose intolerance. Waist circumference and body mass index (BMI) are the established markers of abdominal adiposity and general adiposity, respectively. However, it has not been examined whether these two markers can detect the clustering of metabolic risk factors in Japanese subjects.

METHODS AND RESULTS

We studied 5,796 Japanese middle-aged subjects aged 40-60 years (4,344 males and 1,452 females). Metabolic risk factors including high blood pressure, dyslipidemia, and glucose intolerance were identified according to the diagnostic criteria for metabolic syndrome in Japan. The number of metabolic risk factors was significantly associated with the BMI values in both male and female subjects. The prevalence of subjects with multiple (two or more) metabolic risk factors was 29.4% and 7.6% in males and females, respectively. According to receiver operating characteristic (ROC) analysis, the area under curve values of BMI and waist circumference did not differ in male (0.658 vs. 0.671, p=n.s.) and female (0.776 vs. 0.790, p=n.s.) subjects, indicating that the waist circumference as well as the BMI could be useful in detecting the occurrence of multiple metabolic risk factors. The appropriate cut-off values of BMI to predict the presence of multiple metabolic risk factors were 24.7 and 23.4 kg/m(2) in males and females, respectively. The sensitivity and specificity using these cut-off values were 58 and 65% in males and 65 and 77% in females, respectively.

CONCLUSION

The BMI values can similarly predict the presence of multiple metabolic risk factors just as the waist circumference in Japanese middle-aged subjects.

Impact of body mass index and the metabolic syndrome on the risk of cardiovascular disease and death in middle-aged men

BACKGROUND

The purpose of this study was to investigate associations between combinations of body mass index (BMI) categories and metabolic syndrome (MetS) and the risk of cardiovascular disease and death in middle-aged men.

METHODS AND RESULTS

At age 50 years, cardiovascular risk factors were assessed in 1758 participants without diabetes in the community-based Uppsala Longitudinal Study of Adult Men (ULSAM). According to BMI-MetS status, they were categorized as normal weight (BMI <25 kg/m(2)) without MetS (National Cholesterol Education Program criteria; n=891), normal weight with MetS (n=64), overweight (BMI 25 to 30 kg/m(2)) without MetS (n=582), overweight with MetS (n=125), obese (BMI >30 kg/m(2)) without MetS (n=30), or obese with MetS (n=66). During follow-up (median 30 years), 788 participants died, and 681 developed cardiovascular disease (composite of cardiovascular death or hospitalization for myocardial infarction, stroke, or heart failure). In Cox proportional-hazards models that adjusted for age, smoking, and low-density lipoprotein cholesterol, an increased risk for cardiovascular disease was observed in normal-weight participants with MetS (hazard ratio 1.63, 95% confidence interval 1.11 to 2.37), overweight participants without MetS (hazard ratio 1.52, 95% confidence interval 1.28 to 1.80), overweight participants with MetS (hazard ratio 1.74, 95% confidence interval 1.32 to 2.30), obese participants without MetS (hazard ratio 1.95, 95% confidence interval 1.14 to 3.34), and obese participants with MetS (hazard ratio 2.55, 95% confidence interval 1.81 to 3.58) compared with normal-weight individuals without MetS. These BMI-MetS categories significantly predicted total mortality rate in a similar pattern.

CONCLUSIONS

Middle-aged men with MetS had increased risk for cardiovascular events and total death regardless of BMI status during more than 30 years of follow-up. In contrast to previous reports, overweight and obese individuals without MetS also had an increased risk. The present data refute the notion that overweight and obesity without MetS are benign conditions.

The association between BMI and mortality using offspring BMI as an indicator of own BMI: large intergenerational mortality study

OBJECTIVES

To obtain valid estimates of the association between body mass index (BMI) and mortality by using offspring BMI as an instrumental variable for own BMI.

DESIGN

Cohort study based on record linkage, with 50 years of follow-up for mortality. Associations of offspring BMI with all cause and cause specific maternal and paternal mortality were estimated as hazard ratios per standard deviation of offspring BMI.

SETTING

A large intergenerational prospective population based database covering the general population of Sweden.

PARTICIPANTS

More than one million Swedish parent-son pairs.

RESULTS

The final dataset analysed contained information on 1 018 012 mother-son pairs (122 677 maternal deaths) and 1 004 617 father-son pairs (242 126 paternal deaths). For some causes of death, the patterns of associations between offspring BMI and mortality were similar to those seen for own BMI and mortality in previous studies. Parental mortality from diabetes, coronary heart disease, and kidney cancer had the strongest positive associations with offspring BMI (for example, hazard ratio (HR) for coronary heart disease per standard deviation increase in offspring BMI for mothers 1.15, 95% CI 1.14 to 1.17 and for fathers 1.10, 1.09 to 1.11). However, in contrast to the inverse association of own BMI with lung cancer and respiratory disease mortality seen in other studies, there was a positive association between offspring BMI and lung cancer mortality in mothers (1.12, 1.09 to 1.15) and fathers (1.03, 1.02 to 1.05) and between offspring BMI and respiratory mortality in mothers (1.05, 1.02 to 1.08) and fathers (1.02, 1.00 to 1.04). Associations of own BMI and offspring BMI with all cause, cardiovascular disease related, and non-cardiovascular disease related mortality were compared in a subset of father-son pairs (n=72 815). When offspring BMI was used as an instrumental variable for paternal BMI, the causal association between BMI and paternal cardiovascular disease mortality (HR per standard deviation of BMI 1.82, 95% CI 1.17 to 2.83) was stronger than that indicated by the directly observed association between own BMI and cardiovascular disease mortality (1.45, 1.31 to 1.61).

CONCLUSIONS

Use of offspring BMI as a predictor of own BMI, a technique that avoids problems of reverse causality, suggests that positive associations of BMI with all cause and cardiovascular mortality may be underestimated in conventional observational studies. Use of offspring BMI instead of own BMI in analyses of respiratory disease and lung cancer mortality, for which previous studies have reported consistent and strong inverse associations with own BMI, suggests that such studies have overstated the apparent adverse consequences of lower BMI with respect to these outcomes.

Obesity: focus on all-cause mortality and cancer

Excess body weight is a strong determinant as well as modifiable risk factor for all-cause and cancer mortality, and as such carries the potential for primary prevention. Recently published studies greatly enhance our knowledge about the impact of body fat distribution on relative risks specific to cancer type, and among women, there is further evidence for the role of menopausal status in modifying relative risks. However, the magnitude of all-cause as well as cancer mortality related to excess body weight varies between prospective cohort studies and the strength of the association, in particular in the overweight range, is still a matter of debate. The distribution of total body fat, how we measure it, and the ratio of body fat to fat-free mass explains to some degree the inconsistencies in associated disease risks in the literature. Physical activity, a potential confounder, has been shown to lower the risk of many chronic diseases, independently of the degree of adiposity. A review of the literature provides much support for public health messages that advocate the benefit of change to a more active lifestyle regardless of age and level of excess body fat.

Periprostatic fat measured on computed tomography as a marker for prostate cancer aggressiveness

Objective

Several reports found that obesity was associated with prostate cancer (PC) aggressiveness among men treated with radical prostatectomy or radiotherapy. Studies concerning this issue have basically relied on body mass index (BMI), as a marker for general obesity. Because visceral fat is the most metabolic active fat, we sought to evaluate if periprostatic fat measured on a computed tomography (CT) is a better marker than BMI to predict PC aggressiveness in a Dutch population who underwent brachytherapy for localized PC.

Patients and methods

Of the 902 patients who underwent brachytherapy, 725 CT scans were available. Subcutaneous fat thickness (CFT), periprostatic fat area (cm²) and fat-density (%) were determined on the CT scan. Patients were stratified into three groups: <25, 25–75 and >75 percentile of the fat-density. Associations between the three fat-density subgroups and BMI and PC aggressiveness were examined.

Results

237 patients were classified as having normal weight (37.2%), 320 as overweight (50.2%) and 80 as obese (12.6%). There was a strong significant association between BMI and fat-density and CFT. The strongest correlation was seen between BMI and CFT (Pearson r coefficient = 0.71). Logistic regression analysis revealed no statistically significant association between the different fat measurements and the risk of having a high-risk disease.

Conclusions

Periprostatic fat and fat-density as measured with CT were not correlated with PC aggressiveness in patients receiving brachytherapy. However, 31% of the patients with a normal BMI had a fat-density of >75 percentile of the periprostatic fat-density.

Fasting plasma glucose in the screening for type 2 diabetes in morbidly obese subjects

BACKGROUND

Higher mortality rates among morbidly obese (BMI of > or =40 or > or =35 kg/m2 with weight-related comorbidities) subjects are mainly explained by comorbidities such as type 2 diabetes. As bariatric surgery ameliorates diabetes, obese diabetic subjects will receive great benefits from bariatric surgery. Screening for diabetes prior to surgical referral is therefore crucial.

METHODS

We studied 1,253 consecutively recruited (2005-2008) morbidly obese subjects (67% women). Among subjects without known diabetes, 70% (670/961) performed an oral glucose tolerance test (OGTT). Screen-detected diabetes was defined as fasting plasma glucose (fPG) > or =7.0 mmol/l and/or 2-h glucose concentration (2hPG) > or = 11.1 mmol/l.

RESULTS

Within the study population, 31% had diabetes, of which 8% were screen-detected. Eighty percent of those with screen-detected diabetes were diagnosed by fPG. In subjects with nondiabetic fPG concentrations, elevating the fPG cutoff value from 5.2 mmol/l to the World Health Organization's (WHO's) recommended value of 6.1 mmol/l reduced the percentage of the population needing an OGTT considerably (78-23%), but only slightly reduced the sensitivity of fPG in detecting a diabetic 2hPG concentration (100-77%). Only 7% of the patients with fPG between 6.1 and 6.9 mmol/l had a diabetic 2hPG concentration. Following the WHO's recommendations, we found that 95% of all subjects with unknown diabetes were identified.

CONCLUSIONS

Fasting glucose identified four out of five morbidly obese subjects with unknown diabetes. A supplemental OGTT in selected persons identified the majority of the remaining diabetic cases.

BMI, waist circumference, and mortality according to health status in the older adult population of Spain

Among the explanations proposed for the weak and inconsistent association between BMI and mortality in the elderly are the lack of adjustment for waist circumference (WC) and that the association varies with health status. This work examines the independent association of BMI and WC with mortality in older adults, and the influence of health status on this association. A cohort of 3,536 persons representative of the Spanish population aged >or=60 years was selected in 2000 and 2001, and followed prospectively until 2007. The analyses were performed with Cox models and adjusted for the main confounders. During follow-up, 659 persons died (18.6% of the cohort). Before adjusting for WC, mortality in the upper quartile of BMI was 15% lower than in the lower quartile (hazard ratio (HR): 0.85; 95% confidence interval (CI): 0.66-1.08; P for linear trend = 0.076). After adjusting for WC, the association was even stronger, so that mortality in the upper quartile of BMI was 37% lower than in the lower quartile (HR: 0.63; 95% CI: 0.45-0.88; P for linear trend < 0.003). Before adjusting for BMI, no association was observed between WC and mortality. After adjusting for BMI, WC was positively associated with mortality (HR for upper vs. lower quartile of WC: 1.48; 95% CI: 1.07-2.05; P for linear trend = 0.008). These associations were mainly observed in those with limitations in mobility and agility. BMI has an inverse, and WC has a direct, independent association with mortality in older adults, particularly in those with worse health status.

Fitness and abdominal obesity are independently associated with cardiovascular risk

OBJECTIVES

To examine the relationship between cardiovascular fitness (VO(2)max) and abdominal obesity (waist circumference) and individual cardiovascular disease (CVD) risk factors, as well as a clustered risk factor profile, and to study the impact of gender, age and smoking on these relationships.

DESIGN

Cross-sectional.

SETTING

Astrand Laboratory of Work Physiology, Swedish School of Sport and Health Sciences, Stockholm, Sweden.

SUBJECTS

Men (n = 781) and women (n = 890) from two random population-based samples of Swedish women and men aged 20 to 65 years.

MAIN OUTCOMES

Odds ratios.

RESULTS

Each unit of higher fitness was associated with a decrease in all individual risk factors ranging from 2% to 4% independent of waist circumference, each unit of higher waist circumference was associated with an increased risk ranging from 2% to 5% independent of fitness. For clustering of three or more of the risk factors, each unit of fitness was associated with a 5% decrease in risk and each unit of waist circumference with a 5% increase in risk. The clustered risk was higher in unfit participants who were older or smoked daily, regardless of waist circumference. Obese participants were at higher risk if they were men or older, regardless of fitness level. However, neither a higher fitness level nor lean status reduced the risk associated with smoking.

CONCLUSIONS

Higher fitness and lower waist circumference are each independently associated to a similar extent with a lower CVD risk. Simultaneous evaluation of both fitness and abdominal obesity status in clinical practice is important.

Far from easy and accurate - detection of metabolic syndrome by general practitioners

Background

Metabolic syndrome (MetS) is a major public health challenge. General practitioners (GPs) could play a key role in its recognition. However, it often remains undiagnosed in primary care. This study assesses how well GPs and patients recognise MetS among patients with coronary heart disease or at least one of its risk factors.

Methods

Twenty-six health centres around Finland were randomly selected for the purpose of identifying, over a two-week period in April 2005, patients meeting the inclusion criteria of coronary heart disease or one of its risk factors. GPs and identified patients (n = 1880) were asked to complete surveys that included a question about the patient's MetS status. A trained nurse conducted health checks (n = 1180) of the identified patients, utilising criteria of MetS modified from the National Cholesterol Program. Data from the GPs' survey were compared with those from the health check to establish the extent of congruence of identification of MetS.

Results

Almost half (49.4%) of the patients met the criteria of MetS as established by objective measures. However, in the GPs' survey responses, only 28.5% of the patients were identified as having MetS. Additionally, these groups of MetS patients were not congruent. The sensitivity of the GPs' diagnosis of MetS was 0.31 with a specificity of 0.73. Only 7.1% of the study patients stated that they were suffering from MetS.

Conclusion

Detection of MetS is inaccurate among GPs in Finland. Most patients were not aware of having MetS. The practical relevance of MetS in primary care should be reconsidered.

Adiposity indicators and dementia over 32 years in Sweden

BACKGROUND

High midlife and late-life adiposity may increase risk for dementia. Late-life decrease in body mass index (BMI) or body weight within several years of a dementia diagnosis has also been reported. Differences in study designs and analyses may provide different pictures of this relationship.

METHODS

Thirty-two years of longitudinal body weight, BMI, waist circumference, and waist-to-hip ratio (WHR) data, from the Prospective Population Study of Women in Sweden, were related to dementia. A representative sample of 1,462 nondemented women was followed from 1968 at ages 38-60 years, and subsequently in 1974, 1980, 1992, and 2000, using neuropsychiatric, anthropometric, clinical, and other measurements. Cox proportional hazards regression models estimated incident dementia risk by baseline factors. Logistic regression models including measures at each examination were related to dementia among surviving participants 32 years later.

RESULTS

While Cox models showed no association between baseline anthropometric factors and dementia risk, logistic models showed that a midlife WHR greater than 0.80 increased risk for dementia approximately twofold (odds ratio 2.22, 95% confidence interval 1.00-4.94, p = 0.049) among surviving participants. Evidence for reverse causality was observed for body weight, BMI, and waist circumference in years preceding dementia diagnosis.

CONCLUSIONS

Among survivors to age 70, high midlife waist-to-hip ratio may increase odds of dementia. Traditional Cox models do not evidence this relationship. Changing anthropometric parameters in years preceding dementia onset indicate the dynamic nature of this seemingly simple relationship. There are midlife and late-life implications for dementia prevention, and analytical considerations related to identifying risk factors for dementia.

Usefulness of triglycerides-to-high-density lipoprotein cholesterol ratio for predicting the first coronary event in men

Overweight and obesity potentiate the development of cardiovascular risk factors but many doubts have arisen recently regarding their role in coronary events. We evaluated the predictive value of a surrogate maker of insulin resistance, the ratio of triglyceride (TG) to high-density lipoprotein (HDL), for the incidence of a first coronary event in men workers according to body mass index (BMI). We designed a case-control study of active subjects collected from a single factory through their annual health examination and medical reports. Case subjects included those with myocardial infarction, unstable angina pectoris, or subclinical myocardial ischemia detected through electrocardiographic abnormalities. The sample was constituted by 208 case and 2,080 control subjects (mean age 49.9 years, 49.6 to 50.2). General characteristics of case and control subjects were well matched. The TG/HDL ratio was significantly higher in case subjects compared to controls. Stratification of the sample revealed an increasing prevalence of case subjects and mean TG/HDL in each category of BMI. Multivariable analysis, adjusted by smoking, demonstrated that TG/HDL increased 50% the risk of a first coronary event (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.26 to 1.71), whereas low-density lipoprotein cholesterol values indicated a more moderate increased risk (OR 1.01, 95% CI 1.005 to 1.012); metabolic syndrome (OR 1.76, 95% CI 0.94 to 3.30) and hypertension (OR 1.50, 95% CI 0.81 to 2.79) did not reach statistical significance. The TG/HDL ratio was associated with a first coronary event in all categories of BMI. In conclusion, the TG/HDL ratio has a high predictive value of a first coronary event regardless of BMI.

Prostate cancer survivorship: prevention and treatment of the adverse effects of androgen deprivation therapy

BACKGROUND

More than one-third of the estimated 2 million prostate cancer survivors in the United States receive androgen deprivation therapy (ADT). This population of mostly older men is medically vulnerable to a variety of treatment-associated adverse effects.

MEASUREMENTS AND RESULTS

Androgen-deprivation therapy (ADT) causes loss of libido, vasomotor flushing, anemia, and fatigue. More recently, ADT has been shown to accelerate bone loss, increase fat mass, increase cholesterol and triglycerides, and decrease insulin sensitivity. Consistent with these adverse metabolic effects, ADT has also recently been associated with greater risks for fractures, diabetes and cardiovascular disease.

CONCLUSION

Primary care clinicians and patients should be aware of the potential benefits and harms of ADT. Screening and intervention to prevent treatment-related morbidity should be incorporated into the routine care of prostate cancer survivors. Evidence-based guidelines to prevent fractures, diabetes, and cardiovascular disease in prostate cancer survivors represent an important unmet need. We recommend the adapted use of established practice guidelines designed for the general population.

Waist circumference in primary care

Current literature suggests that waist circumference may be marginally better than BMI as a surrogate marker for total body fat and can identify thinner people with increased visceral adipose tissue and increased cardiometabolic risk. This commentary explores the use of WC in primary care, including how and when to measure, and how to use the results.

The origin of intermuscular adipose tissue and its pathophysiological implications

The intermuscular adipose tissue (IMAT) is a depot of adipocytes located between muscle bundles. Several investigations have recently been carried out to define the phenotype, the functional characteristics, and the origin of the adipocytes present in this depot. Among the different mechanisms that could be responsible for the accumulation of fat in this site, the dysdifferentiation of muscle-derived stem cells or other mesenchymal progenitors has been postulated, turning them into cells with an adipocyte phenotype. In particular, muscle satellite cells (SCs), a heterogeneous stem cell population characterized by plasticity and self-renewal that allow muscular growth and regeneration, can acquire features of adipocytes, including the abilities to express adipocyte-specific genes and accumulate lipids. Failure to express the transcription factors that direct mesenchymal precursors into fully differentiated functionally specialized cells may be responsible for their phenotypic switch into the adipogenic lineage. We proved that human SCs also possess a clear adipogenic potential that could explain the presence of mature adipocytes within skeletal muscle. This occurs under some pathological conditions (i.e., primary myodystrophies, obesity, hyperglycemia, high plasma free fatty acids, hypoxia, etc.) or as a consequence of thiazolidinedione treatment or simply because of a sedentary lifestyle or during aging. Several pathways and factors (PPARs, WNT growth factors, myokines, GEF-GAP-Rho, p66(shc), mitochondrial ROS production, PKCβ) could be implicated in the adipogenic conversion of SCs. The understanding of the molecular pathways that regulate muscle-to-fat conversion and SC behavior could explain the increase in IMAT depots that characterize many metabolic diseases and age-related sarcopenia.

Secular trends in adiposity in Norwegian 9-year-olds from 1999-2000 to 2005

Background

Due to the negative health consequences of childhood obesity monitoring trends in body mass and adiposity is essential. The purpose of this study was to describe secular trends in the prevalence of overweight and obesity among 9-year-old children, and to study changes in adiposity and fat distribution by investigating changes in waist circumference (WC) and skinfold thicknesses.

Methods

A total of 859 9-year-olds were included in two cross-sectional studies conducted in 1999-2000 and 2005. Measurements of body mass index (BMI; in kg/m²), WC and skinfold thicknesses were taken by trained investigators. The International Obesity Task Force cut-offs were used to define overweight and obese subjects.

Results

The overall prevalence of overweight (including obesity) did not change over the five year period. However, a shift may have occurred as the prevalence of overweight (including obesity) increased by 6.4% in girls and 5.5% in boys over the five year period. In both study periods, logistic regression analyses revealed that children of non-Western origin had 2 times higher odds of being overweight/obese than those of Western origin. However, neither the children of Western origin nor the children of non-Western origin showed a significant increase in the prevalence of overweight over the five-year period. No changes were observed for mean BMI, while a significant increase in WC was reported for both girls and boys, and an increase in all skinfold measurements was observed in girls only. Shifts in percentile distribution were observed for BMI, WC and sum of 4 skinfold thickness, however, the shift appeared to be faster in the upper end of the population distribution (p < 0.001 for interactions).

Conclusion

From 1999-2000 to 2005, there have been increases in 9-year-olds measures of adiposity even though the BMI did not change. The results indicate the need of a large-scale monitoring of adiposity, in addition to BMI, in children.

The effect of preoperative body mass index on outcome after temporal lobe epilepsy surgery

PURPOSE

The increasing prevalence of obesity is a significant health care concern. Individuals with obesity, i.e., a body mass index (BMI)>or=30, may have significant comorbid conditions that may increase the risk of general anesthesia and operative procedures. The rationale for the present investigation is to evaluate the importance of obesity on operative outcome in patients with intractable temporal lobe epilepsy undergoing surgical treatment.

METHODS

This study involved a retrospective analysis of 244 adult patients who underwent epilepsy surgery at Mayo Clinic in Rochester, Minnesota between 1990 and 1996. The mean age of patients at surgery was 35 years (range, 18-68 years). There were 108 male patients (44%). Seventy-three patients (30%) were overweight (BMI 26-29), 56 patients (23%) were obese (BMI 30-39), and nine patients (4%) had extreme obesity (BMI>or=40) at the time of surgery.

RESULTS

The BMI was not predictive of the duration of intensive care unit or hospital stay following surgery, perioperative morbidity, or long-term seizure control following epilepsy surgery. Fifteen deaths occurred in the study period remote from the surgical procedure. The mortality during follow-up was increased for patients with extreme obese (p<0.007).

CONCLUSIONS

The perioperative morbidity and seizure outcome following epilepsy surgery was independent of the patient's body weight. However, long-term mortality was significantly increased in the individuals with extreme obesity. The effect of morbid obesity on long-term quality of life after epilepsy surgery may need to be considered in selecting operative candidates.

Exercise program affects body composition but not weight in postmenopausal women

The aim of this study was to investigate the effect of a 12-month moderate-to-vigorous exercise program combining aerobic and muscle strength training on body composition among sedentary, postmenopausal women.

METHODS

A randomized controlled trial was conducted. A total of 189 sedentary postmenopausal women (age 50-69 y, body mass index 22-40 kg/m2) were randomly assigned to an exercise (n = 96) or a control group (n = 93). Study parameters measured at baseline, 4 months, and 12 months were as follows: body weight and body height (body mass index), waist and hip circumference (body fat distribution), and dual-energy x-ray absorptiometry (total body fat and lean mass). Differences in changes in study parameters between exercise and control group were examined with generalized estimating equations analysis.

RESULTS

The exercise program did not result in significant effects on weight, body mass index, and hip circumference. The exercise group experienced a statistically significant greater loss in total body fat, both absolute (-0.33 kg) (borderline) as in a percentage (-0.43%) compared with the control group. In addition, lean mass increased significantly (+0.31 kg), whereas waist circumference (-0.57 cm) decreased significantly compared with the control group.

CONCLUSIONS

We conclude that a 12-month exercise program combining aerobic and muscle strength training did not affect weight but positively influenced body composition of postmenopausal women. Affecting body fat distribution and waist circumference may have important health implications because it is an independent risk factor in obese but also in nonobese people. Therefore, this study gives further credence to efforts of public health and general practitioners aiming to increase physical activity levels of postmenopausal women.

The liver and the waistline: Fifty years of growth

Fifty years of the Gastroenterological Society of Australia have witnessed the changing appearance of Australians. Asian immigration has transformed the dominant urban culture from European to Eurasian, with some unique Australian attributes. Meanwhile, global conditions have altered body shape, and our sports-proud country is now fat! Thus, as in North America, Europe, China, and affluent Asia-Pacific countries, prosperity and lifestyle, cheap processed foods coupled with reduced physical activity have created an epidemic of over-nutrition resulting in overweight/obesity. Additional genetic factors are at the core of the apple shape (central obesity) that typifies over-nourished persons with metabolic syndrome. Indigenous Australians, once the leanest and fittest humans, now have exceedingly high rates of obesity and type 2 diabetes, contributing to shorter life expectancy; Asian Australians are also at higher risk. Like non-steroidal anti-inflammatory drugs (NSAIDs) and cigarette smoking, obesity now contributes much to gastrointestinal morbidity and mortality (gastroesophageal reflux disease, cancers, gallstones, endoscopy complications). This review focuses on Australian research about fatty liver, particularly roles of central obesity/insulin resistance in non-alcoholic fatty liver disease/steatohepatitis (NAFLD/NASH). The outputs include many highly cited original articles and reviews and the first book on NAFLD. Studies have identified community prevalence, clinical outcomes, association with insulin resistance, metabolic syndrome and hypoadiponectinemia, developed and explored animal models for mechanisms of inflammation and fibrosis, conceptualized etiopathogenesis, and demonstrated that NASH can be reversed by lowering body weight and increasing physical activity. The findings have led to development of regional guidelines on NAFLD, the first internationally, and should now inform daily practice of gastroenterologists.

Prediction of body composition from spine and hip bone densitometry

Body mass index (BMI) is used to assess overweight and obesity, but it does not account for the distribution or composition of excess weight. Dual-energy X-ray absorptiometry (DXA) is widely used for the assessment of osteoporosis. We hypothesized that measures of regional fat tissue composition from spine and hip DXA done for osteoporosis assessment could be used to estimate body composition more accurately than with BMI. We identified 427 adult patients who underwent DXA evaluation of the lumbar spine, hip, and whole body at the same visit. The population was randomly divided into 2 equal-sized subgroups: one used to derive prediction equations for whole-body fat tissue, whole-body lean tissue, and trunk fat tissue, and the other for independent validation. The estimates were compared with the actual measurements from the whole-body scans. In all analyses, prediction using the regional DXA scans outperformed prediction using BMI or its component variables, height and weight. When the predicted and actual measurements were compared in the validation cohort, regression slopes did not differ significantly from unity and the intercepts did not differ significantly from zero. We conclude that regional DXA scans of the spine and hip can be used to accurately measure body composition. Further research is needed to see whether these measures can in turn predict the metabolic complications associated with overweight and obesity.

Role of visceral adipose tissue in aging

BACKGROUND

Visceral fat (VF) accretion is a hallmark of aging in humans. Epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes, cardiovascular disease, metabolic syndrome and death.

METHODS

Studies utilizing novel rodent models of visceral obesity and surgical strategies in humans have been undertaken to determine if subcutaneous (SC) abdominal or VF are causally linked to age-related diseases.

RESULTS

Specific depletion or expansion of the VF depot using genetic or surgical tools in rodents has been shown to have direct effects on disease risk. In contrast, surgically removing large quantities of SC fat does not consistently improve metabolic parameters in humans or rodents, while benefits were observed with SC fat expansion in mice, suggesting that SC fat accrual is not an important contributor to metabolic decline. There is also compelling evidence in humans that abdominal obesity is a stronger risk factor for mortality risk than general obesity. Likewise, we have shown that surgical removal of VF improves mean and maximum lifespan in rats, providing the first causal evidence that VF depletion may be an important underlying cause of improved lifespan with caloric restriction.

GENERAL SIGNIFICANCE

This review provides both corollary and causal evidence for the importance of accounting for body fat distribution, and specifically VF, when assessing disease and mortality risk. Given the hazards of VF accumulation on health, treatment strategies aimed at selectively depleting VF should be considered as a viable tool to effectively reduce disease risk in humans.

Waist-hip-ratio as a predictor of all-cause mortality in high-functioning older adults

PURPOSE

The relationship between obesity and mortality in older adults is debated, with concern that body mass index (BMI) may be an imperfect measure of obesity in this age group. We assessed the relationship between three measures of obesity and all-cause mortality in a group of healthy older adults.

METHODS

We analyzed data from the MacArthur Successful Aging Study, a longitudinal study of high-functioning men and women, ages 70-79 years at baseline. We examined 12-year, all-cause mortality risk by BMI, waist circumference, and waist-to-hip circumference ratio (WHR). Proportional hazards regression was used to adjust for gender, race, baseline age, and smoking status. We tested for obesity interactions with gender, race, and smoking status and conducted stratified analyses based on the results of interaction testing.

RESULTS

There was no association between all-cause mortality and BMI or waist circumference in either unadjusted or adjusted analyses. In contrast, all-cause mortality increased with WHR. There was an interaction with sex, so that there was a graded relationship between WHR and mortality in women (relative hazard, 1.28 per 0.1 increase in WHR; 95% confidence interval, 1.05-1.55) and a threshold relationship in men (relative hazard 1.75 for WHR>1.0 compared to WHR< or =1.0; 95% confidence interval, 1.06-2.91).

CONCLUSION

WHR rather than BMI appears to be the more appropriate yardstick for risk stratification of high-functioning older adults.

Obesity genes identified in genome-wide association studies are associated with adiposity measures and potentially with nutrient-specific food preference

BACKGROUND

New genetic loci, most of which are expressed in the brain, have recently been reported to contribute to the development of obesity. The brain, especially the hypothalamus, is strongly involved in regulating weight and food intake.

OBJECTIVES

We investigated whether the recently reported obesity loci are associated with measures of abdominal adiposity and whether these variants affect dietary energy or macronutrient intake.

DESIGN

We studied 1700 female Dutch participants in the European Prospective Investigation into Cancer and Nutrition (EPIC). Their anthropometric measurements and intake of macronutrients were available. Genotyping was performed by using KASPar chemistry. A linear regression model, with an assumption of an additive effect, was used to analyze the association between genotypes of 12 single nucleotide polymorphisms (SNPs) and adiposity measures and dietary intake.

RESULTS

Seven SNPs were associated (P < 0.05) with weight, body mass index (BMI), and waist circumference (unadjusted for BMI). They were in or near to 6 loci: FTO, MC4R, KCTD15, MTCH2, NEGR1, and BDNF. Five SNPs were associated with dietary intake (P < 0.05) and were in or near 5 loci: SH2B1 (particularly with increased fat), KCTD15 (particularly with carbohydrate intake), MTCH2, NEGR1, and BDNF.

CONCLUSIONS

We confirmed some of the findings for the newly identified obesity loci that are associated with general adiposity in a healthy Dutch female population. Our results suggest that these loci are not specifically associated with abdominal adiposity but more generally with obesity. We also found that some of the SNPs were associated with macronutrient-specific food intake.

Optimal waist:height ratio cut-off point for cardiometabolic risk factors in Turkish adults

Objective

To identify the optimal waist:height ratio (WHtR) cut-off point that discriminates cardiometabolic risk factors in Turkish adults.

Design

Cross-sectional study. Hypertension, dyslipidaemia, diabetes, metabolic syndrome score ≥2 (presence of two or more metabolic syndrome components except for waist circumference) and at least one risk factor (diabetes, hypertension or dyslipidaemia) were categorical outcome variables. Receiver-operating characteristic (ROC) curves were prepared by plotting 1 − specificity on the x-axis and sensitivity on the y-axis. The WHtR value that had the highest Youden index was selected as the optimal cut-off point for each cardiometabolic risk factor (Youden index = sensitivity + specificity − 1).

Setting

Turkey, 2003.

Subjects

Adults (1121 women and 571 men) aged 18 years and over were examined.

Results

Analysis of ROC coordinate tables showed that the optimal cut-off value ranged between 0·55 and 0·60 and was almost equal between men and women. The sensitivities of the identified cut-offs were between 0·63 and 0·81, the specificities were between 0·42 and 0·71 and the accuracies were between 0·65 and 0·73, for men and women. The cut-off point of 0·59 was the most frequently identified value for discrimination of the studied cardiometabolic risk factors. Subjects classified as having WHtR ≥ 0·59 had significantly higher age and sociodemographic multivariable-adjusted odds ratios for cardiometabolic risk factors than subjects with WHtR < 0·59, except for diabetes in men.

Conclusions

We show that the optimal WHtR cut-off point to discriminate cardiometabolic risk factors is 0·59 in Turkish adults.

Increases in body mass index over a 7-year period and risk of cause-specific mortality in Korean men

BACKGROUND

The association between increased body mass index (BMI) and subsequent mortality remains unclear in Asians. This study investigated the associations between BMI increases and cause-specific mortality in middle-aged Korean men.

METHODS

We conducted a retrospective cohort study of 473 358 Korean men aged 30-64 years, who had undergone health examinations in both 1992 and 1998 and were followed up during 1998-2004. Cox proportional hazards for cause-specific 7-year mortality in relation to BMI changes after stratification of baseline BMI status were analysed.

RESULTS

Mortality from cardiovascular disease (CVD) was associated with BMI in both 1992 and 1998. Non-CVD mortality was inversely associated with BMI in both 1992 and 1998. We cross-classified participants into groups based on their baseline BMI levels and percent BMI changes during follow-up; men with the lowest BMI level at baseline (BMI in 1992 <21 kg/m(2)) and stable BMI during follow-up (percent change in BMI <5%) were included in the reference category. Compared with the reference group, CVD mortality was higher in initially obese men (BMI in 1992 > or =25 kg/m(2)) with any increase of BMI, and in initially lean men (BMI in 1992 <21 kg/m(2)) or initially overweight men (BMI in 1992 23-24.9 kg/m(2)) with BMI increases of > or =10%. BMI increases of 5.0-9.9% in men with baseline BMI <25 kg/m(2) and stable BMI in men with baseline BMI > or =21 kg/m(2) appeared to lower the risk for non-CVD or all-cause mortality, to below the levels seen in the reference group.

CONCLUSIONS

Among middle-aged Korean men, obesity or severe weight gain was detrimental to CVD mortality. An increase in BMI appeared to have a predictive value for CVD mortality, especially when used in combination with baseline BMI level. In contrast, moderate weight gain in non-obese men seemed to protect against non-CVD and all-cause mortality.

The Mediterranean diet protects against waist circumference enlargement in 12Ala carriers for the PPARγ gene: 2 years' follow-up of 774 subjects at high cardiovascular risk

The PPARγ gene regulates insulin sensitivity and adipogenesis. The Pro12Ala polymorphism of this gene has been related to fat accumulation. Our aim was to analyse the effects of a 2-year nutritional intervention with Mediterranean-style diets on adiposity in high-cardiovascular risk patients depending on the Pro12Ala polymorphism of the PPARγ gene. The population consisted of a substudy (774 high-risk subjects aged 55–80 years) of the Prevención con Dieta Mediterránea (PREDIMED) randomised trial aimed at assessing the effect of the Mediterranean diet for CVD prevention. There were three nutritional intervention groups: two of them of a Mediterranean-style diet and the third was a control group advised to follow a conventional low-fat diet. All the participants were genotyped by PCR-restriction fragment length polymorphism (RFLP). The results showed that carriers of the 12Ala allele allocated to the control group had a statistically significant higher change in waist circumference (adjusted difference coefficient = 2·37 cm; P = 0·014) compared with wild-type subjects after 2 years of nutritional intervention. This adverse effect was not observed among 12Ala carriers allocated to both Mediterranean diet groups. In diabetic patients a statistically significant interaction between Mediterranean diet and the 12Ala allele regarding waist circumference change was observed ( − 5·85 cm; P = 0·003). In conclusion, the Mediterranean diet seems to be able to reduce waist circumference in a high-cardiovascular risk population, reversing the negative effect that the 12Ala allele carriers of the PPARγ gene appeared to have. The beneficial effect of this dietary pattern seems to be higher among type 2 diabetic subjects.

The diseasome of physical inactivity--and the role of myokines in muscle--fat cross talk

Type 2 diabetes, cardiovascular diseases, colon cancer, breast cancer, dementia and depression constitute a cluster of diseases, which defines 'a diseasome of physical inactivity'. Both physical inactivity and abdominal adiposity, reflecting accumulation of visceral fat mass, are associated with the occurrence of the diseases within the diseasome. Physical inactivity appears to be an independent and strong risk factor for accumulation of visceral fat, which again is a source of systemic inflammation. Chronic inflammation is involved in the pathogenesis of insulin resistance, atherosclerosis, neurodegeneration and tumour growth. Evidence suggests that the protective effect of exercise may to some extent be ascribed to the anti-inflammatory effect of regular exercise, which can be mediated via a reduction in visceral fat mass and/or by induction of an anti-inflammatory environment with each bout of exercise. The finding that muscles produce and release myokines provides a conceptual basis to understand the mechanisms whereby exercise influences metabolism and exerts anti-inflammatory effects. According to our theory, contracting skeletal muscles release myokines, which work in a hormone-like fashion, exerting specific endocrine effects on visceral fat. Other myokines work locally within the muscle via paracrine mechanisms, exerting their effects on signalling pathways involved in fat oxidation.

Abdominal adiposity is associated with elevated C-reactive protein independent of BMI in healthy nonobese people

OBJECTIVE

There is debate over the most appropriate adiposity markers of obesity-associated health risks. We evaluated the relationship between fat distribution and high-sensitivity C-reactive protein (hs-CRP), independent of total adiposity.

RESEARCH DESIGN AND METHODS

We studied 350 people with abdominal adiposity (waist-to-hip ratio [WHR] > or =0.9 in male and > or =0.85 in female subjects) and 199 control subjects (WHR <0.9 in male and <0.85 in female subjects) matched for BMI and age. We measured hs-CRP and major cardiovascular risk factors.

RESULTS

Participants with abdominal adiposity had BMI similar to that in control subjects (24.8 +/- 2.5 vs. 24.7 +/- 2.2 kg/m(2), respectively), but significantly higher waist circumference (96.4 +/- 6.0 vs. 83.3 +/- 6.7 cm; P < 0.01) and WHR (1.07 +/- 0.08 vs. 0.85 +/- 0.05; P < 0.001). Compared with the control subjects, participants with abdominal adiposity had an adverse cardiovascular risk factor profile, significantly higher hs-CRP (1.96 +/- 2.60 vs. 1.53 +/- 1.74 mg/dl; P < 0.01), and a twofold prevalence of elevated CRP values (>3 mg/dl).

CONCLUSIONS

In nonobese people, moderate abdominal adiposity is associated with markers of subclinical inflammation independent of BMI.

Relationship between adiposity and cardiovascular risk factors in prevalent hemodialysis patients

OBJECTIVE

Increased body mass index (BMI) is associated with reduced all-cause and cardiovascular (CV) mortality in hemodialysis (HD) patients, whereas CV risk increases with BMI in the general population. In the general population, obesity is associated with inflammation, decreased high-density lipoprotein (HDL) cholesterol, increased low-density lipoprotein (LDL) cholesterol, and triglycerides (TGs), all risk factors for CV disease. Low-density lipoprotein cholesterol does not predict CV risk in HD, whereas increased C-reactive protein and interleukin-6 (IL-6), low HDL and apolipoprotein (apo) AI, and increased fasting TGs do predict risk. Renal failure is associated with dyslipidemia and inflammation in normal-weight patients. We hypothesized that the effects of obesity may be obscured by renal failure in HD.

METHODS

We explored the relationship between adipose tissue pools and distribution, i.e., subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) (measured by magnetic resonance imaging) and measures of inflammation (C-reactive protein, IL-6, ceruloplasmin, and alpha1 acid glycoprotein), HDL and LDL cholesterol, total TGs, apo AI, apo B, apo CII (an activator of lipoprotein lipase), apo CIII (an inhibitor of lipoprotein lipase), and the adipokines, leptin and adiponectin, in 48 patients with prevalent HD.

RESULTS AND CONCLUSIONS

Total TG concentrations were positively correlated with VAT controlled for age, sex, and weight. Both apo CII and apo CIII were correlated only with VAT. Adiponectin was inversely correlated with VAT, and leptin was positively associated with SAT. C-reactive protein and alpha1 acid glycoprotein were weakly associated with SAT, whereas ceruloplasmin was strongly associated with VAT according to multiple regression analysis. In contrast, apo B, LDL, apo AI, HDL, and IL-6 were not correlated with any measure of body composition, potentially mitigating the effects of obesity in HD.

Cardiac health: primary prevention of heart disease in women

Heart disease is the number one cause of death among women. Although 450,000 women die annually from heart disease, this fact is unknown to many women. Because heart disease is frequently preventable, increasing awareness of personal risk and preventative measures is a key element of health care for women. Nurse clinicians can evaluate, educate, and counsel women regarding their risk for this pervasive disease and promote behavior changes that will decrease that risk. Research evidence supports that lifestyle behaviors are the cornerstone of heart disease prevention. This article presents current evidence for the prevention of heart disease related to dietary intake, physical activity, weight management, smoking cessation, blood pressure control, and lipid management. Guidelines for implementing findings in clinical practice are discussed.

Primary and secondary prevention of cardiovascular diseases: a practical evidence-based approach

Despite the fact that we possess highly effective tools for the primary and secondary prevention of myocardial infarction and other complications of atherosclerosis, coronary heart disease remains the most common cause of death in our society. Arterial inflammation and endothelial dysfunction play central roles in the pathogenesis of atherosclerosis and adverse cardiovascular (CV) events. Therapeutic lifestyle changes in conjunction with an aggressive multidrug regimen targeted toward the normalization of the major CV risk factors will neutralize the atherogenic milieu, reduce vascular inflammation, and markedly decrease the risk of adverse CV events and need for revascularization procedures. Specific CV risk factors and optimal therapies for primary and secondary prevention are discussed.

Primary and secondary prevention of cardiovascular diseases: a practical evidence-based approach

Despite the fact that we possess highly effective tools for the primary and secondary prevention of myocardial infarction and other complications of atherosclerosis, coronary heart disease remains the most common cause of death in our society. Arterial inflammation and endothelial dysfunction play central roles in the pathogenesis of atherosclerosis and adverse cardiovascular (CV) events. Therapeutic lifestyle changes in conjunction with an aggressive multidrug regimen targeted toward the normalization of the major CV risk factors will neutralize the atherogenic milieu, reduce vascular inflammation, and markedly decrease the risk of adverse CV events and need for revascularization procedures. Specific CV risk factors and optimal therapies for primary and secondary prevention are discussed.

Metabolic diseases and associated complications: sex and gender matter!

BACKGROUND

Clinicians and health professionals are increasingly challenged to understand and consider the different health needs of women and men. The increase of gender awareness and the expanding science of gender medicine will affect more and more clinical practice. This review addresses gender-specific aspects in metabolic disorders and related complications, which represent an increasing burden of this century and a great challenge to public health.

DESIGN

There is increasing evidence of gender-related differences in risk factors, clinical manifestation and sequelae of obesity and diabetes and increasing knowledge that prevention, detection and therapy of illness affect men and women differently.

RESULTS

Some gender-specific aspects, especially regarding cardiovascular disease, have been studied in more detail, but for many complications sex-related analyses of the results of both clinical trials and basic science are still missing or disregarded. Impaired glucose and lipid metabolism as well as dysregulation of energy balance and body fat distribution have a great impact on overall health via neuroendocrine changes and inflammatory pathways and deteriorate the course of many diseases with particular harm for women. Metabolic diseases dramatically affect life of men and women from infancy up to old age and are a major challenge for women during pregnancy. Great impact is attached to the intrauterine period and the lifelong implications of fetal programming.

CONCLUSIONS

Initiation of prospective studies on the impact of gender as primary outcome and investigation of gender-related pathophysiological mechanisms of chronic diseases will help to improve patient care and to implement evidence-based gender-specific prevention programs and clinical recommendations in future.

Measurement error and ethnic comparisons of measures of abdominal obesity

BACKGROUND

Methods of estimating central obesity are important because of the increasing frequency of obesity related diseases worldwide. Here we evaluate the precision of measuring waist circumference and the waist to hip ratio with comparisons across ethnic groups.

METHODS

The third Australian Risk Factor Prevalence Study (1989) of 9279 adults recorded height, weight, and Body Mass Index together with duplicate measurements of the waist and hip circumferences, the waist to hip ratio, and blood pressure levels using clearly defined survey techniques. Measurement error and precision for these variables were calculated, and comparisons were made across ethnic groups.

RESULTS

Coefficients of variation for the waist circumference and the waist to hip ratio were less than 1% indicating good precision in comparison with quite large variability for systolic and diastolic pressure readings. Waist circumference showed increased variability in subjects with larger body build in comparison with waist to hip ratio. Equivalence tests across ethnic groups indicated that the waist to hip ratio was independent of ethnicity.

CONCLUSION

Waist to hip ratio provides a superior measure of central obesity with low measurement error, high precision, and no bias over a wide range of ethnic groups. We believe that it is essential to standardize methods in the assessment of central obesity. Assessment criteria should be based on waist to hip ratio rather than waist circumference.

[Which complementary studies and metabolic monitoring must be performed in OSAS? For which patients?]

Characterised by abnormal breathing during sleep, obstructive sleep apnea (OSA) is strongly associated with obesity. Visceral obesity is a component of metabolic syndrome with insulin resistance, hypertension and dyslipidemia. OSA may also represent an independent risk factor for cardiovascular disease, especially hypertension, diabetes mellitus and dyslipidemia. Abdominal adiposity is an important factor for the development of OSA and associated metabolic disorders. Diagnosis of metabolic syndrome can be made using usual markers like waist circumference, arterial pressure measurement, fasting blood glucose, fasting cholesterol, triglyceride and HDL-cholesterol. Those parameters should be systematically evaluated in case of OSA.

Waist circumference and waist/hip ratio in relation to all-cause mortality, cancer and sleep apnea

Abdominal obesity assessed by waist or waist/hip ratio are both related to increased risk of all-cause mortality throughout the range of body mass index (BMI). The relative risks (RRs) seem to be relatively stronger in younger than in older adults and in those with relatively low BMI compared with those with high BMI. Absolute risks and risk differences are preferable measures of risk in a public health context but these are rarely presented. There is a great lack of studies in ethnic groups (groups of African and Asian descent particularly). Current cut-points as recommended by the World Health Organization seem appropriate, although it may be that BMI-specific and ethnic-specific waist cut-points may be warranted. Waist alone could replace both waist-hip ratio and BMI as a single risk factor for all-cause mortality. There is much less evidence for waist to replace BMI for cancer risk mainly because of the relative lack of prospective cohort studies on waist and cancer risk. Obesity is also a risk factor for sleep apnoea where neck circumference seems to give the strongest association, and waist-hip ratio is a risk factor especially in severe obstructive sleep apnoea syndrome. The waist circumference and waist-hip ratio seem to be better indicators of all-cause mortality than BMI.

Obesity and overweight prevalences in rural and urban populations in East Spain and its association with undiagnosed hypertension and Diabetes Mellitus: a cross-sectional population-based survey

Background

An increase in the number of overweight and obese subjects in the general population has been observed.

The aim of this study was to determine the prevalence of overweight and obese subjects in the general population and its association with undiagnosed pathologies, such as diabetes mellitus [DM] and hypertension [HT], by taking age, gender and place of residence [rural or urban] into account.

Findings

A cross-sectional population-based survey was conducted in Castellón, East Spain in 2005–2006. The sample included 2,062 participants aged 18–94 years. Weight, height, blood pressure and glycaemia values were recorded, and information about gender, age and place of residence was obtained. Overweight, obesity, and undiagnosed HT and DM prevalences were calculated. Multiple regression analyses were done to assess the association of overweight/obesity with undiagnosed HT and DM by adjusting for age, gender and place of residence.

The overall overweight, obesity, and undiagnosed HT and DM prevalences were 39.9% [95% CI:37.3–42.0], 25.9% [95% CI:24.0–27.9], 9.0% [95% CI:7.8–10.4] and 12.6% [95% CI:11.2–14.1], respectively. We identified various independent risk factors; those relating to overweight were increasing age, male gender and rural residential area, while that relating to obesity was increasing age. Compared to normal weight adults, the Relative Prevalence Ratio (RPR) for subjects who were overweight and had HT was 2.00 [95% CI:1.21–3.32]; that for obesity and HT was 1.91 [95% CI:1.48–2.46], and it was 1.50 [95% CI:1.25–1.81] for obesity and DM.

Conclusion

Overweight and obesity prevalences, and their association with undiagnosed DM and HT, are high in our study population.

Survival in older men may benefit from being slightly overweight and centrally obese--a 5-year follow-up study in 4,000 older adults using DXA

BACKGROUND

Whether overweight in old age is hazardous remains controversial. Body mass index (BMI) overestimates adiposity and fails to measure central adiposity. We used dual-energy x-ray absorptiometry (DXA) to measure adiposity and hypothesized that overall adiposity, distribution of adiposity, and muscle mass might individually affect survival.

METHODS

We recruited 2000 men and 2000 women aged 65 years or older. Baseline BMI, waist-hip ratio (WHR), body fat index (BFI = total body fat/height square), relative truncal fat (RTF = trunk fat/total body fat), and body muscle mass index (BMMI = total body muscle mass/height square) were measured. Mortality was ascertained by death registry after 63.3 (median) months.

RESULTS

Two hundred and forty-two men and 78 women died. In men, mortality hazard ratio (HR) decreased consistently by 0.85 (p < .005), 0.86 (p < .005), and 0.86 (p < .005) per every quintile increase in BMI, BFI, and BMMI, respectively. A J-shaped relationship was observed in central adiposity (RTF and WHR) quintiles; the minimum values were at the 3rd WHR quintile (0.92-0.94) and 4th RTF quintile (mean WHR, 0.94). When RTF was tested with BFI, both high and low central adiposity were unfavorable while general adiposity became marginally insignificant (p = 0.062). When BFI and BMMI were tested together, increasing adiposity rather than muscle mass favored survival (BFI quintile, HR 0.97, p .015; BMMI quintile, HR 1.00, p .997).

CONCLUSIONS

Older men were resistive to hazards of overweight and adiposity; and mild-grade overweight, obesity, and even central obesity might be protective. This may bear significant implication on the recommended cutoff values for BMI and WHR in the older population.

Effects of switching from lopinavir/ritonavir to atazanavir/ritonavir on muscle glucose uptake and visceral fat in HIV-infected patients

OBJECTIVE

To determine the effects of switching from lopinavir/ritonavir (LPV/r) to atazanavir/ritonavir (ATV/r) on muscle glucose uptake, glucose homeostasis, lipids, and body composition.

METHODS

Fifteen HIV-infected men and women on a regimen containing LPV/r and with evidence of hyperinsulinemia and/or dyslipidemia were randomized to continue LPV/r or to switch to ATV/r (ATV 300 mg and ritonavir 100 mg daily) for 6 months. The primary endpoint was change in thigh muscle glucose uptake as measured by positron emission tomography. Secondary endpoints included abdominal visceral adipose tissue, fasting lipids, and safety parameters. The difference over time between treatment groups (treatment effect of ATV/r relative to LPV/r) was determined by repeated measures ANCOVA.

RESULTS

After 6 months, anterior thigh muscle glucose uptake increased significantly (treatment effect +18.2 +/- 5.9 micromol/kg per min, ATV/r vs. LPV/r, P = 0.035), and visceral adipose tissue area decreased significantly in individuals who switched to ATV/r (treatment effect -31 +/- 11 cm, ATV/r vs. LPV/r, P = 0.047). Switching to ATV/r significantly decreased triglyceride (treatment effect -182 +/- 64 mg/dl, ATV/r vs. LPV/r, P = 0.02) and total cholesterol (treatment effect -23 +/- 8 mg/dl, ATV/r vs. LPV/r, P = 0.01), whereas high-density lipoprotein and low-density lipoprotein did not change significantly. Fasting glucose also decreased significantly following switch to ATV/r (treatment effect -15 +/- 4 mg/dl, ATV/r vs. LPV/r, P = 0.002).

CONCLUSION

Switching from LPV/r to ATV/r significantly increases glucose uptake by muscle, decreases abdominal visceral adipose tissue, improves lipid parameters, and decreases fasting glucose over 6 months.