Background High Body Mass Index Research Articles

The Effect of HIV and the Modifying Effect of Anti-Retroviral Therapy (ART) on Body Mass Index (BMI) and Blood Pressure Levels in Rural South Africa.

BackgroundHigh BMI and blood pressure are leading chronic disease risk factors in South Africa. Longterm effects of HIV and ART on adiposity and blood pressure are poorly understood, and direct comparisons of risk factor trajectories in HIV- versus HIV+ populations are rare.MethodsIn 2003 and 2010, height, weight, and blood pressure were recorded in a study population (n = 505) in KwaZulu-Natal, South Africa (30% adult HIV prevalence). We modeled change in BMI and BP longitudinally in HIV- individuals (n = 315), seroconverters (n = 32), HIV+ patients not on ART (HIV+ART−; n = 52), HIV+ patients on ART for 0–<2 years as of 2010 (HIV+ART0–<2 yrs; n = 18), patients on ART for 2–5 years (HIV+ART2–5yrs; n = 44), and a subgroup with unknown HIV status (n = 44). Difference-in-differences were assessed in reference to the HIV- population.ResultsBetween 2003 and 2010, BMI increased significantly in the HIV- group, by 0.874 (95% CI 0.339, 1.41; p = 0.001), to 30.4. BMI drop was significantly greater in HIV+ART0-<2yrs than in HIV+ART2–5yrs (p = 0.005). DID in BMI in HIV+ART0-<2yrs versus the reference was -5.21 (95% CI -7.53, -2.90; p = 0.001), and DID in HIV+ART2–5yrs versus reference was -1.35 (95% CI -2.89, 0.189; p = 0.086). DID in SBP in HIV+ART−vs HIV- DID was -7.55 mmHg (95% CI -13.2 to -1.90; p = 0.009).ConclusionShort-term ART (0–<2 years) was associated with larger weight loss than either no ART or long-term ART. Once on ART for 2+ years, individuals ‘caught up’ on weight gain with the HIV- population. Our results showcase the importance of health system readiness to address the burgeoning double burden of disease in South Africa.

Duration of Adulthood Overweight, Obesity, and Cancer Risk in the Women's Health Initiative: A Longitudinal Study from the United States.

BackgroundHigh body mass index (BMI) has become the leading risk factor of disease burden in high-income countries. While recent studies have suggested that the risk of cancer related to obesity is mediated by time, insights into the dose-response relationship and the cumulative impact of overweight and obesity during the life course on cancer risk remain scarce. To our knowledge, this study is the first to assess the impact of adulthood overweight and obesity duration on the risk of cancer in a large cohort of postmenopausal women.Methods and FindingsParticipants from the observational study of the Women’s Health Initiative (WHI) with BMI information from at least three occasions during follow-up, free of cancer at baseline, and with complete covariate information were included (n = 73,913). Trajectories of BMI across ages were estimated using a quadratic growth model; overweight duration (BMI ≥ 25 kg/m2), obesity duration (BMI ≥ 30 kg/m2), and weighted cumulative overweight and obese years, which take into account the degree of overweight and obesity over time (a measure similar to pack-years of cigarette smoking), were calculated using predicted BMIs. Cox proportional hazard models were applied to determine the cancer risk associated with overweight and obesity duration. In secondary analyses, the influence of important effect modifiers and confounders, such as smoking status, postmenopausal hormone use, and ethnicity, was assessed. A longer duration of overweight was significantly associated with the incidence of all obesity-related cancers (hazard ratio [HR] per 10-y increment: 1.07, 95% CI 1.06–1.09). For postmenopausal breast and endometrial cancer, every 10-y increase in adulthood overweight duration was associated with a 5% and 17% increase in risk, respectively. On adjusting for intensity of overweight, these figures rose to 8% and 37%, respectively. Risks of postmenopausal breast and endometrial cancer related to overweight duration were much more pronounced in women who never used postmenopausal hormones. This study has limitations because some of the anthropometric information was obtained from retrospective self-reports. Furthermore, data from longitudinal studies with long-term follow-up and repeated anthropometric measures are typically subject to missing data at various time points, which was also the case in this study. Yet, this limitation was partially overcome by using growth curve models, which enabled us to impute data at missing time points for each participant.ConclusionsIn summary, this study showed that a longer duration of overweight and obesity is associated with an increased risk of developing several forms of cancer. Furthermore, the degree of overweight experienced during adulthood seemed to play an important role in the risk of developing cancer, especially for endometrial cancer. Although the observational nature of our study precludes inferring causality or making clinical recommendations, our findings suggest that reducing overweight duration in adulthood could reduce cancer risk and that obesity prevention is important from early onset. If this is true, health care teams should recognize the potential of obesity management in cancer prevention and that excess body weight in women is important to manage regardless of the age of the patient.

Interactive effects of physical fitness and body mass index on risk of stroke: A national cohort study.

High body mass index (BMI) and low physical fitness are risk factors for stroke, but their interactive effects are unknown. Elucidation of interactions between these modifiable risk factors can help inform preventive interventions in susceptible subgroups. National cohort study of all 1,547,294 military conscripts in Sweden during 1969-1997 (97-98% of all 18-year-old males). Standardized aerobic capacity, muscular strength, and body mass index measurements were examined in relation to stroke identified from inpatient and outpatient diagnoses through 2012 (maximum age 62 years). Sixteen thousand nine hundred seventy-nine men were diagnosed with stroke in 39.7 million person-years of follow-up. High body mass index, low aerobic fitness, and (less strongly) low muscular fitness were associated with higher risk of any stroke, ischemic stroke, and intracerebral hemorrhage, independently of family history and sociodemographic factors. High body mass index (overweight/obese vs. normal) and low aerobic capacity (lowest vs. highest tertile) had similar effect magnitudes, and their combination was associated with highest stroke risk (incidence rate ratio, 2.36; 95% CI, 2.14-2.60; P < 0.001). Aerobic capacity and muscular strength had a positive additive and multiplicative interaction (P < 0.001), indicating that low aerobic capacity accounted for more strokes among men with low compared with high muscular strength. High body mass index and low aerobic capacity in late adolescence are associated with increased risk of stroke in adulthood. Low aerobic capacity and low muscular strength also have a synergistic effect on stroke risk. These findings suggest that preventive interventions should include weight control and aerobic fitness early in life, and muscular fitness especially among those with low aerobic capacity.

Complementary Role of Arm Circumference to Body Mass Index in Risk Stratification in Heart Failure

ObjectivesThis study was performed to investigate the complementary role of arm circumference to body mass index (BMI) in risk stratification of patients with heart failure (HF). BackgroundHigh BMI is associated with improved survival in patients with HF. However, it does not discriminate between fat and lean muscle as a predominant factor. MethodsBMI, waist circumference (WC), and mid-upper arm circumference (MUAC) were evaluated in 570 consecutive Japanese patients with HF (mean age 67.4 ± 14.0 years). Patients were stratified into low and high groups according to BMI, WC, and MUAC and combined into low- or high-BMI and low- or high-WC groups or low- or high-BMI and low- or high-MUAC groups. The endpoint was all-cause mortality. ResultsSeventy deaths occurred over a median follow-up period of 1.5 years (interquartile range: 0.7 to 2.8 years). After adjusting for several pre-existing prognostic factors, including Seattle Heart Failure Score and exercise capacity, BMI (hazard ratio [HR]: 0.68; p = 0.016), WC (HR: 0.76; p = 0.044), and MUAC (HR: 0.52; p < 0.001) were all inversely associated with prognosis. Compared with the high-BMI/high-WC group, both the low-BMI/high-WC and low-BMI/low-WC groups showed comparably poorer prognosis. However, the low-BMI/low-MUAC group but not the low-BMI/high-MUAC group showed poorer prognosis than the high-BMI/high-MUAC group. Adding MUAC to BMI (0.70 vs. 0.63, p = 0.012) but not WC to BMI (0.64 vs. 0.63, p = 0.763) significantly increased the area under the curve on receiver-operating characteristic curve analysis. ConclusionsMUAC, but not WC, plays a complementary role to BMI in predicting prognosis in patients with HF.

Body Mass Index More Than 45 kg/m2 as a Cutoff Point Is Associated With Dramatically Increased Postoperative Complications in Total Knee Arthroplasty and Total Hip Arthroplasty

BackgroundHigher body mass index (BMI) has been associated with postoperative complications in total knee arthroplasty (TKA) and total hip arthroplasty (THA). However, the association of incremental increases of BMI and its effects on postoperative complications has not been well studied. We hypothesize that there is a BMI cutoff at which there is a significant increase of the risk of postoperative complications. MethodsWe studied the American College of Surgeons National Surgical Quality Improvement Program from 2006 to 2013. The final cohort included 77,785 primary TKA and 49,475 primary THA subjects, respectively. Patients were separated into 7 groups based on BMI (18.5-24.9 kg/m2, 25.0-29.9 kg/m2, 30.0-34.9 kg/m2, 35.0-39.9 kg/m2, 40.0-44.9 kg/m2, 45.0-49.9 kg/m2, and >50.0 kg/m2). We analyzed data on five 30-day composite complication variables, including any complication, major complication, wound infection, systemic infection, and cardiac and/or pulmonary complication. ResultsThe odds ratio for 4 (any complication, major complication, wound infection, and systemic infection) of 5 composite complications started to increase exponentially once BMI reached 45.0 kg/m2 or higher in TKA. Similarly, the odds ratio in 3 (any complication, systemic infection, and wound infection) of 5 composite complications showed similar trends in THA patients. These findings were further confirmed with propensity score matching and entropy balancing. ConclusionsOur study suggested that there was a positive correlation between BMI and incidences of 30-day postoperative complications in both TKA and THA. The odds of complications increased dramatically once BMI reached 45.0 kg/m2.

Association of Body Mass Index With Increased Cost of Care and Length of Stay for Emergency Department Patients With Chest Pain and Dyspnea

High body mass index (BMI) increases the probability of indeterminate findings on diagnostic studies, length of stay, and cost of care for hospitalized patients. No study has examined the economic and operational impact of BMI in patients with chest complaints presenting to the emergency department (ED). The objective was to measure the association of BMI with the main outcomes of cost of care, length of stay (including time in the ED and time in the wards if admitted), and radiation exposure in patients presenting to the ED with chest pain and dyspnea. This was a prospective, 4-center, outcomes study. Patients were adults with dyspnea and chest pain, nondiagnostic electrocardiograms, and no obvious diagnosis. Patients were followed for the main outcomes for 90 days. Outcomes that were stratified by BMI in 5 categories, underweight, normal weight, overweight, obese, and morbidly obese, were compared using the Kruskall-Wallis rank test, and the independent predictive value of BMI was tested with multivariate regressions. Compared with medical costs for normal weight patients, costs were 22% higher for overweight patients (P=0.077), 28% higher for obese patients (P=0.020), and 41% higher for morbidly obese patients (P=0.015). Morbidly obese patients without computerized tomographic scanning stayed in the hospital 34% longer than normal weight patients (P=0.073), and morbidly obese patients with computerized tomographic scanning stayed in the hospital 44% longer than normal weight patients (P=0.083). BMI was not a significant predictor of radiation exposure. Morbidly obese patients had the highest proportion (87%) of no significant cardiopulmonary diagnosis for 90 days after computerized tomographic pulmonary angiography. BMI was associated with increases in cost of care and length of hospital stay for patients with chest pain and dyspnea. These results emphasize a need for specific protocols to manage morbidly obese patients presenting to the ED with chest pain and dyspnea. Clinical Trial Registration- http://www.clinicaltrials.gov. Unique identifier: NCT01059500.

Prediagnosis Body Mass Index, Physical Activity, and Mortality in Endometrial Cancer Patients

Background Higher body mass index (BMI) and inactivity have been associated with a higher risk of developing endometrial cancer, but the impact on endometrial cancer survival is unclear. Methods Among incident endometrial cancer case subjects in the National Institutes of Health-AARP Diet and Health Study, we examined associations of prediagnosis BMI (n = 1400) and physical activity (n = 875) with overall and disease-specific 5- and 10-year mortality. Using Cox proportional hazards regression, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for tumor characteristics, treatment, and other risk factors. All statistical tests were two-sided. Results Compared with women with a BMI in the range of 18.5 to less than 25kg/m(2), the hazard ratios for 5-year all-cause mortality were 1.74 (95% CI = 1.13 to 2.66) for BMI in the range of 25 to less than 30kg/m(2), 1.84 (95% CI = 1.17 to 2.88) for BMI in the range of 30 to less than 35kg/m(2), and 2.35 (95% CI = 1.48 to 3.73) for BMI greater than or equal to 35kg/m(2) (P trend < .001). Higher BMI was also statistically significantly associated with poorer endometrial cancer-specific but not cardiovascular disease 5-year mortality. Hazard ratio estimates for 10-year all-cause and endometrial cancer-specific mortality as related to BMI were similar to 5-year hazard ratio estimates, whereas 10-year cardiovascular disease mortality became statistically significant (HR = 4.08; 95% CI = 1.56 to 10.71 comparing extreme BMI groups). More physical activity was related to lower all-cause 5-year mortality (HR = 0.57, 95% CI = 0.33 to 0.98 for >7 hours/week vs never/rarely), but the association was attenuated after adjustment for BMI (HR = 0.64, 95% CI = 0.37 to 1.12). No association was observed between physical activity and disease-specific mortality. Conclusions Our findings suggest that higher prediagnosis BMI increases risk of overall and disease-specific mortality among women diagnosed with endometrial cancer, whereas physical activity lowers risk. Intervention studies of the effect of these modifiable lifestyle factors on mortality are needed.

Higher Caesarean Section Rates in Women With Higher Body Mass Index: Are We Managing Labour Differently?

BackgroundHigher body mass index has been associated with an increased risk of Caesarean section. The effect of differences in labour management on this association has not yet been evaluated. MethodsWe conducted a cohort study using data from the McGill Obstetrics and Neonatal Database for deliveries taking place during a 10-year period. Women’s BMI at delivery was categorized as normal (20 to 24.9), overweight (25 to 29.9), obese (30 to 39.9), or morbidly obese (≥40). We evaluated the effect of the management of labour on the need for Caesarean section using unconditional logistic regression models. ResultsData were available for 11 922 women, of whom 2289 women had normal weight, 5663 were overweight, 3730 were obese, and 240 were morbidly obese. After adjustment for known confounding variables, increased BMI category was associated with an overall increase in the use of oxytocin and in the use of epidural analgesia, and with a decrease in use of forceps and vacuum extraction among second stage deliveries. Higher BMI was also found to be associated with earlier decisions to perform a Caesarean section in the second stage of labour. When adjusted for these differences in the management of labour, the increasing rate of Caesarean section observed with increasing BMI category was markedly attenuated (P < 0.001). ConclusionWomen with an increased BMI are managed differently in labour than women of normal weight. This difference in management in part explains the increased rate of Caesarean section observed with higher BMI.

Waist Circumference, Body Mass Index, and Survival in Systolic Heart Failure: The Obesity Paradox Revisited

Background Higher body mass index (BMI) is associated with improved heart failure (HF) survival, but the role of waist circumference (WC) in HF outcomes has not been studied. Methods and Results A total of 344 patients with advanced systolic HF had WC and BMI measured at presentation. High WC was defined as ≥88 cm in women and ≥102 cm in men, and high BMI as ≥25 kg/m 2. Two-year urgent heart transplant (UT)–free survival in high vs normal WC groups was 77.9% vs 64.3% ( P = .025) and in high vs normal BMI was 89.8% vs 58.2% ( P < .001). After multivariable adjustment, normal WC compared with high WC was associated with higher all-cause mortality (risk ratio [RR] 2.76, 95% confidence interval [CI] 1.34–5.71) and higher risk of death/UT (RR 2.14, 95% CI 1.25–3.68). The best outcomes were seen in those with both high WC and high BMI. Conclusions High WC, an alternative anthropometric index of obesity more specific to abdominal adiposity, high BMI, and the combination of high WC/high BMI were each associated with improved outcomes in this advanced HF cohort, lending further support for an obesity paradox in HF. The role of body composition in HF survival should be a focus of future investigation.

Are we addressing the perinatal risks for women with high BMI?

BackgroundHigh body mass index (BMI) is a major risk factor for developing maternal complications such as thromboembolism (TE) and pressure sores. More than half of all mothers who died have...

High Body Mass Index is Not Associated With Coronary Artery Disease in Angina Patients With Chronic Kidney Disease: A Coronary Angiography Study

High body mass index (BMI) is an established risk factor for coronary artery disease (CAD) in the general population. This relationship is less clear in CAD patients with different stages of chronic kidney disease (CKD) because many complications of CKD can cause malnutrition and low BMI. We studied the association of BMI and angiography-confirmed CAD in CKD patients. Thousand one hundred thirty-three patients admitted for coronary angiography was stratified by CKD classification. Demographic, clinical, hemodynamic, and angiographic findings were assessed. CKD patients (n = 980) were divided into angiographic CAD and non-CAD groups to compare traditional CAD risk factors. Patients with angiography-confirmed CAD (n = 496) were further analyzed for the association between BMI and CAD risk at different stages of CKD patients. Mean BMI was 27.4 +/- 4.1, 27.7 +/- 4.0, 25.9 +/- 3.5, 24.2 +/- 3.8, 23.2 +/- 3.0 and 23.8 +/- 4.2 kg/m for normal renal function, stage I, II, III, IV, and V CKD patients, respectively. Male, old age, presence of CKD, diabetes, hypertension, smoking, and higher cholesterol had significant association with angiographic CAD in the CKD sub-cohort. Obesity was not related to CAD in the CKD sub-cohort. Using WHO category for obesity, mild CKD patients were more likely to be overweight (62.8%) and obese (72%); meanwhile, most moderate and severe CKD patients were not obese (P < 0.05). Only 17.6% and 18.8% of moderate and severe CKD patients were obese (P < 0.05), by Taiwan classification. High BMI was not associated with angiographic CAD in CKD patients with angina.

The effect of leisure-time physical activity on the risk of acute myocardial infarction depending on Body Mass Index: a population-based case-control study

BackgroundHigh body mass index (BMI) and lack of physical activity have been recognized as important risk factors for coronary heart disease. The aim of the present study was to evaluate whether leisure-time physical activity compensates for the increased risk of acute myocardial infarction associated with overweight and obesity.MethodsData from the SHEEP (Stockholm Heart Epidemiology Program) study were used. The SHEEP study is a large Swedish population-based case-control study, comprising 1204 male and 550 female cases, and 1538 male and 777 female controls, conducted in Stockholm County, Sweden, during the period 1992–1994. Odds ratios (OR), together with 95 % confidence intervals (95% CI), were calculated using unconditional logistic regression, as estimates of the relative risks.ResultsRegular leisure-time physical activity was associated with a decreased risk of myocardial infarction among lean, normal-weight and overweight subjects, but not among obese subjects. Obese (BMI ≥ 30) and physically active persons had an almost twofold risk of myocardial infarction, compared with normal-weight and sedentary persons (OR 1.85, 95% CI 1.07–3.18). The results were similar for men and women.ConclusionWhile regular leisure-time physical activity seems to provide protection against myocardial infarction among lean, normal-weight and overweight subjects, this does not appear to be the case in obese subjects.