Optimal Body Mass Index Cut-off Point for Predicting Colorectal Cancer Survival in an Asian Population: A National Health Information Database Analysis.
ABSTRACT: The optimal body mass index (BMI) range for predicting survival in Asian colorectal cancer patients is unknown. We established the most appropriate cut-off point of BMI to predict better survival in Asian colorectal cancer patients using a two-stage approach. Two cohorts of colorectal cancer patients were included in this study: 5815 hospital-based development cohort and 54,043 nationwide validation cohort. To determine the optimal BMI cut-off point at diagnosis, the method of Contal and O'Quigley was used. We evaluated the association between BMI and overall survival (OS) using the Cox proportional hazard model. During a median follow-up of 5.7 and 5.1 years for the development and the validation cohort, 1180 (20.3%) and 10,244 (19.0%) deaths occurred, respectively. The optimal cut-off of BMI identified as 20.2 kg/m2 (plog-rank < 8.0 × 10-16) for differentiating between poorer and better OS in the development cohort. When compared to the patients with a BMI < 20.2 kg/m2, the patients with a BMI ? 20.2 kg/m2 had a significantly better OS (HR = 0.62, 95% CI = 0.54-0.72, p = 1.1 × 10-10). The association was validated in the nationwide cohort, showing better OS in patients with a BMI ? 20.2 kg/m2 (HR = 0.64, 95% CI = 0.60-0.67, p < 0.01). We suggest the use of a BMI value of 20.2 kg/m2 to predict survival in Asian colorectal cancer patients.
Project description:To derive cut-points for body mass index (BMI) and waist circumference (WC) for minority ethnic groups that are risk equivalent based on endogenous glucose levels to cut-points for white Europeans (BMI 30 kg/m2; WC men 102 cm; WC women 88 cm).Cross-sectional data from participants aged 40-75 years: 4,672 white and 1,348 migrant South Asian participants from ADDITION-Leicester (UK) and 985 indigenous South Asians from Jaipur Heart Watch/New Delhi studies (India). Cut-points were derived using fractional polynomial models with fasting and 2-hour glucose as outcomes, and ethnicity, objectively-measured BMI/WC, their interaction and age as covariates.Based on fasting glucose, obesity cut-points were 25 kg/m2 (95% Confidence Interval: 24, 26) for migrant South Asian, and 18 kg/m2 (16, 20) for indigenous South Asian populations. For men, WC cut-points were 90 cm (85, 95) for migrant South Asian, and 87 cm (82, 91) for indigenous South Asian populations. For women, WC cut-points were 77 cm (71, 82) for migrant South Asian, and 54 cm (20, 63) for indigenous South Asian populations. Cut-points based on 2-hour glucose were lower than these.These findings strengthen evidence that health interventions are required at a lower BMI and WC for South Asian individuals. Based on our data and the existing literature, we suggest an obesity threshold of 25 kg/m2 for South Asian individuals, and a very high WC threshold of 90 cm for South Asian men and 77 cm for South Asian women. Further work is required to determine whether lower cut-points are required for indigenous, than migrant, South Asians.
Project description:To investigate the ethnicity-specific association between body mass index (BMI) and diabetes in pregnancy, with a focus on the appropriateness of using BMI cut-offs to identify pregnant women at risk of diabetes.Analysis of routinely-collected data from a maternity unit in London, UK. Data were available on 53 264 women delivering between 2004 and 2012. Logistic regression was used to explore the association between diabetes in pregnancy and BMI among women of different ethnicities, and adjusted probability estimates were used to derive risk equivalent cut-offs. ROC curve analysis was used to assess the performance of BMI as a predictor of diabetes in pregnancy.The prevalence of diabetes in pregnancy was 2.3% overall; highest in South and East Asian women (4.6% and 3.7%). In adjusted analysis, BMI category was strongly associated with diabetes in all ethnic groups. Modelled as a continuous variable with a quadratic term, BMI was an acceptable predictor of diabetes according to ROC curve analysis. Applying a BMI cut-off of 30 kg/m2 would identify just over half of Black women with diabetes in pregnancy, a third of White (32%) and South Asian (35%) women, but only 13% of East Asian women. The 'risk equivalent' (comparable to 30 kg/m2 in White women) threshold for South Asian and East Asian women was approximately 21 kg/m2, and 27.5 kg/m2 for Black women.This study suggests that current BMI thresholds are likely to be ineffective for diabetes screening in South and East Asian women, as many cases of diabetes will occur at low BMI levels. Our results suggest that East Asian women appear to face a similarly high risk of diabetes to South Asian women. Current UK guidelines recommend diabetes screening should be offered to all pregnant South Asian women; extending this recommendation to include women of East Asian ethnicity may be appropriate.
Project description:Purpose:This study evaluated the oncologic impact of obesity, as determined by body mass index (BMI), in patients who underwent laparoscopic surgery for rectal cancer. Methods:The records of 483 patients with stage I-III rectal cancer who underwent laparoscopic surgery between June 2003 and December 2011 were reviewed. A matching model based on BMI was constructed to balance obese and nonobese patients. Cox hazard regression models for overall survival (OS) and disease-free survival (DFS) were used for multivariate analyses. Additional analysis using visceral fat area (VFA) measurement was performed for matched patients. The threshold for obesity was BMI ? 25 kg/m2 or VFA ? 130 cm2. Results:The score matching model yielded 119 patients with a BMI ? 25 kg/m2 (the obese group) and 119 patients with a BMI < 25 kg/m2 (the nonobese group). Surgical outcomes including operation time, estimated blood loss, nil per os periods, and length of hospital stay did not differ between the obese and the nonobese group. The retrieved lymph node numbers and pathologic CRM positive rate were also similar in between the 2 groups. After a median follow-up of 48 months (range, 3-126 months), OS and DFS rates were similar between the 2 groups. A tumor location-adjusted model for overall surgical complications showed that a BMI ? 25 kg/m2 were not risk factors. Multivariable analyses for OS and DFS showed no significant association with a BMI ? 25 kg/m2. Conclusion:Obesity was not associated with long-term oncologic outcomes in patients undergoing laparoscopic surgery for rectal cancer in the Asian population.
Project description:OBJECTIVE:To examine the relationship between body mass index (BMI) and outcomes after percutaneous coronary intervention (PCI) in a multiethnic South East Asian population. SETTING:Fifteen participating cardiology centres contributed to the Malaysian National Cardiovascular Disease Database-Percutaneous Coronary Intervention (NCVD-PCI) registry. PARTICIPANTS:28?742 patients from the NCVD-PCI registry who had their first PCI between January 2007 and December 2014 were included. Those without their BMI recorded or BMI <11?kg/m2 or >70?kg/m2 were excluded. MAIN OUTCOME MEASURES:In-hospital death, major adverse cardiovascular events (MACEs), vascular complications between different BMI groups were examined. Multivariable-adjusted HRs for 1-year mortality after PCI among the BMI groups were also calculated. RESULTS:The patients were divided into four groups; underweight (BMI <18.5?kg/m2), normal BMI (BMI 18.5 to <23?kg/m2), overweight (BMI 23 to <27.5?kg/m2) and obese (BMI ?27.5?kg/m2). Comparison of their baseline characteristics showed that the obese group was younger, had lower prevalence of smoking but higher prevalence of diabetes, hypertension and dyslipidemia. There was no difference found in terms of in-hospital death, MACE and vascular complications after PCI. Multivariable Cox proportional hazard regression analysis showed that compared with normal BMI group the underweight group had a non-significant difference (HR 1.02, p=0.952), while the overweight group had significantly lower risk of 1-year mortality (HR 0.71, p=0.005). The obese group also showed lower HR but this was non-significant (HR 0.78, p=0.056). CONCLUSIONS:Using Asian-specific BMI cut-off points, the overweight group in our study population was independently associated with lower risk of 1-year mortality after PCI compared with the normal BMI group.
Project description:BACKGROUND:Previous studies have revealed that increased body mass index (BMI) is associated with decreased mortality among hemodialysis patients. However, few studies have dealt with the association between BMI and mortality among patients undergoing peritoneal dialysis (PD) and even fewer studies have focused on the Asian PD patients. The reported studies were often non-conclusive and some even yielded contradictory results. This paper, to our best knowledge, registers the first attempt to systematically review the current literature and summarize new results on the association between BMI and mortality among the Asian PD population. METHOD:A systematic literature review was performed in Medline and EMBASE to identify relevant cohort studies on all-cause and cardiovascular disease (CVD) mortality stratified by BMI categories tailored to Asians among the Asian PD population. We meta-analyzed individual results based on a random effect model, strictly complying with Preferred Reporting Items for Systematic Reviews and Meta-analysis. RESULTS:The paper reviews seven cohort studies with a total of 3,610 Asian PD patients. Obese group (BMI = 25-29.9 kg/m2) was associated with higher risk of all-cause mortality (HR = 1.46, 95%CI [1.07-1.98]; p = 0.02) and CVD mortality (HR = 2.01, 95%CI [1.14-3.54]; p = 0.02), compared to the normal group (BMI = 18.5-22.9 kg/m2). The underweight group (BMI<18.5kg/m2) was also associated with an elevated risk of all-cause mortality (HR = 2.11, 95%CI [1.46-3.07]; p<0.001). No significant associations between BMI with all-cause mortality were found among the overweight group (23-24.9 kg/m2) (HR = 1.00, 95%CI [0.76-1.32]; p = 0.9). The association between BMI and CVD mortality risk among the underweight and overweight groups was found nonsignificant (p = 0.5 and 0.6 respectively). CONCLUSION:Obesity is associated with increased mortality in Asian PD patients. The study indicates a "V-shaped" trend in the association between BMI and mortality in these patients.
Project description:Body mass index (BMI) kg/m2 is a key screening tool for under-nutrition in adults, but difficult to obtain in immobile or unwell patients, particuarly in low resource settings, due to inability to accurately measure both weight and height. Mid-upper arm circumference (MUAC) is used to assess under-nutrition in children under 5 years but no standardised cut-off values exist for adults. In a cohort of adult Filipino patients admitted to a tuberculosis ward we assessed (i) cut-offs for MUAC to predict moderate under-nutrition (BMI <17kg/m2), (ii) the performance of limb lengths to predict height and; (iii) associations of body fat percentage from skinfolds and hand grip-strength with BMI. In 303 patients with MUAC and BMI at admission, aged 18-80 years (mean = 45.5, SD:14.8), BMI ranged from 11.2-30.6 kg/m2 and 141 (46.5%) had BMI <17.0 kg/m2. Using receiver operator curves, MUAC cut-offs were identified as <20.5cm for males (sensitivity: 89%, specificity: 84%) and <18.5cm for females (sensitivity: 91%, specificity: 89%), for BMI<17.0 kg/m2. Using published equations, knee height had the lowest mean difference between predicted and measured heights compared to ulnar or demi-span: (-0.98 cm, 95% CI: -1.51/-0.44). Both grip-strength and body fat percentage were positively associated with BMI, in separate linear regression models with exposure-age-sex interactions (adjusted-R-squared values: 0.15, 0.66, respectively). MUAC can predict moderate acute under-nutrition with high positive predictive value. Further research is required to determine the performance of alternative measures to BMI to predict mortality or adverse outcomes in acutely unwell patients.
Project description:<label>BACKGROUND</label>Obesity or overweight is related to worse outcomes in patients with atrial fibrillation (AF) following catheter ablation (CA). The role of being underweight in relation to recurrent arrhythmias post AF ablation is less certain. We conducted a retrospective study to investigate the association of body mass index (BMI) with arrhythmia outcomes in AF patients undergoing CA.<label>METHODS</label>In a cohort of 1410 AF patients (mean age 57.2?±?11.6?years; 68% male) undergoing single CA, the association between BMI and AF ablation outcome was analyzed using BMI as a continuous variable and by four BMI categories (<18.5?kg/m2, 18.5-24?kg/m2, 25-29?kg/m2, and???30?kg/m2).<label>RESULT</label>We observed a positive association between a cut off value of BMI and risk of AF recurrence post AF ablation. BMI ?26.36?kg/m2 was related to more AF recurrence (c-statistic 0.55, 95%CI 0.51-0.58; P?<?0.01) with 50% increased risk of AF recurrence (HR 1.50, 95% CI 1.22-1.86; P?<?0.01). Recurrence rates in the four BMI categories were 33.3%, 23.2%, 27.2 and 41.8%, respectively (P?<?0.01). Kaplan-Meier analysis showed that BMI categories of <18.5?kg/m2 and???30?kg/m2 were all associated with more AF recurrence (P?=?0.01). Both underweight (HR 1.85, 95%CI 1.12-3.08; P?=?0.02) and obesity (HR 1.78, 95%CI 1.17-2.72; P?=?0.01) significantly increased the risk of AF recurrence in a Cox proportional hazard model.<label>CONCLUSION</label>BMI had good predictive value for AF ablation outcomes with a cut off value of ?26.36?kg/m2. Apart from being obese/overweight, being underweight might also be a risk factor for AF recurrence post ablation.
Project description:Body mass index (BMI) cut-off values (>25 and >30) that predict diabetes risk have been well validated in Caucasian populations but less so in Asian populations. We aimed to determine the BMI threshold associated with increased type 2 diabetes (T2DM) risk and to calculate the proportion of T2DM cases attributable to overweight and obesity in the Thai population.Participants were those from the Thai Cohort Study who were diabetes-free in 2005 and were followed-up in 2009 and 2013 (n = 39,021). We used multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the BMI-T2DM association. We modelled non-linear associations using restricted cubic splines. We estimated population attributable fractions (PAF) and the number of T2DM incident cases attributed to overweight and obesity. We also calculated the impact of reducing the prevalence of overweight and obesity on T2DM incidence in the Thai population.Non-linear modelling indicated that the points of inflection where the BMI-T2DM association became statistically significant compared to a reference of 20.00 kg/m2 were 21.60 (OR = 1.27, 95% CI 1.00-1.61) and 20.03 (OR = 1.02, 95% CI 1.02-1.03) for men and women, respectively. Approximately two-thirds of T2DM cases in Thai adults could be attributed to overweight and obesity. Annually, if prevalent obesity was 5% lower, ~13,000 cases of T2DM might be prevented in the Thai population.A BMI cut-point of 22 kg/m2, one point lower than the current 23 kg/m2, would be justified for defining T2DM risk in Thai adults. Lowering obesity prevalence would greatly reduce T2DM incidence.
Project description:Obesity is a well-known risk factor for the development of cancer, but its influence on the course of disease is still controversial. We investigated the influence of body mass index (BMI) on overall survival (OS) in 502 patients with indolent non-Hodgkin's lymphoma or mantle cell lymphoma in a subgroup analysis of the StiL (Study Group Indolent Lymphomas) NHL1 trial. We defined a cut-off of 22.55 kg/m2 by ROC calculation and Youden Index analysis and stratified patients into "low BMI" and "high BMI". Five-year OS was significantly longer in the high BMI group (82.2%) when compared to that of the low BMI group (66.2%) (HR 0.597; 95%CI 0.370-0.963; p = 0.034). BMI was also an independent prognostic factor for OS in multivariate analysis (HR 0.541; 95%CI 0.332-0.883; p = 0.014). Of note, patients had a significantly lower BMI in the presence than patients in the absence of B-symptoms (p = 0.025). BMI significantly impacts on OS in indolent non-Hodgkin's lymphoma and mantle cell lymphoma, which may be influenced by the effect of B-symptoms on BMI.
Project description:BACKGROUND:Body mass index (BMI) overweight/obesity thresholds in South Asian (SA) adults, at equivalent type-2 diabetes risk are lower than for white Europeans (WE). We aimed to define adjusted overweight/obesity thresholds for UK-SA children based on equivalent insulin resistance (HOMA-IR) to WE children. METHODS:In 1138 WE and 1292 SA children aged 9.0-10.9 years, multi-level regression models quantified associations between BMI and HOMA-IR by ethnic group. HOMA-IR levels for WE children were calculated at established overweight/obesity thresholds (at 9.5 years and 10.5 years), based on UK90 BMI cut-offs. Quantified associations in SA children were then used to estimate adjusted SA weight-status thresholds at the calculated HOMA-IR levels. RESULTS:At 9.5 years, current WE BMI overweight and obesity thresholds were 19.2?kg/m2, 21.3?kg/m2 (boys) and 20.0?kg/m2, 22.5?kg/m2 (girls). At equivalent HOMA-IR, SA overweight and obesity thresholds were lower by 2.9?kg/m2 (95% CI: 2.5-3.3?kg/m2) and 3.2?kg/m2 (95% CI: 2.7-3.6?kg/m2) in boys and 3.0?kg/m2 (95% CI: 2.6-3.4?kg/m2) and 3.3?kg/m2 (95% CI: 2.8-3.8?kg/m2) in girls, respectively. At these lower thresholds, overweight/obesity prevalences in SA children were approximately doubled (boys: 61%, girls: 56%). Patterns at 10.5 years were similar. CONCLUSIONS:SA adjusted overweight/obesity thresholds based on equivalent IR were markedly lower than BMI thresholds for WE children, and defined more than half of SA children as overweight/obese.