Browsing by Subject "BMI"
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Item Adiposity has unique influence on the renin-aldosterone axis and blood pressure in black children(Elsevier, 2013-11) Yu, Zhangsheng; Eckert, George; Liu, Hai; Pratt, J. Howard; Tu, Wanzhu; Medicine, School of MedicineOBJECTIVE: To comparatively examine the effects of adiposity on the levels of plasma renin activity (PRA), plasma aldosterone concentration (PAC), and aldosterone-renin ratio (ARR) in young black and white children. STUDY DESIGN: We prospectively assessed 248 black and 345 white children and adolescents. A novel analytical technique was used to assess the concurrent influences of age and body mass index (BMI) on PRA, PAC, and ARR. The estimated effects were depicted by colored contour plots. RESULTS: In contrast to whites, blacks had lower PRA (2.76 vs 3.36 ng/mL/h; P < .001) and lower PAC (9.01 vs 14.59 ng/dL; P < .001). In blacks, BMI was negatively associated with PRA (P = .001), consistent with an association with a more expanded plasma volume; there was no association with PAC. In whites, BMI was positively associated with PAC (P = .005); we did not detect a BMI-PRA association. The effects of BMI on ARR were directionally similar in the two race groups but more pronounced in blacks. Mean systolic blood pressure was greater in blacks with lower PRA (P < .01), higher PAC (P = .015), and higher ARR (P = .49). CONCLUSIONS: An increase in adiposity was associated with a suppressed PRA in blacks and an increase in PAC in whites. The unique relationship between adiposity and renin-aldosterone axis in blacks suggests the possible existence of a population-specific mechanism characterized by volume expansion, which could in turn enhance the influences of adiposity on blood pressure in black children and adolescents.Item Association between body-mass index and quality of split bowel preparation(Elsevier, 2013-11) Fayad, Nabil F.; Kahi, Charles J.; Abd el-jawad, Khaled H.; Shin, Andrea S.; Shah, Shenil; Lane, Kathleen A.; Imperiale, Thomas F.; Medicine, School of MedicineBACKGROUND & AIMS: Little is known about the association between obesity and bowel preparation. We investigated whether body mass index (BMI) is an independent risk factor for inadequate bowel preparation in patients who receive split preparation regimens. METHODS: We performed a retrospective study of data from 2163 consecutive patients (mean age, 60.6 ± 10.5 y; 93.8% male) who received outpatient colonoscopies in 2009 at the Veterans Affairs Medical Center in Indianapolis, Indiana. All patients received a split preparation, categorized as adequate (excellent or good, based on the Aronchick scale) or inadequate. We performed a multivariable analysis to identify factors independently associated with inadequate preparation. RESULTS: Bowel preparation quality was inadequate for 44.2% of patients; these patients had significantly higher mean BMIs than patients with adequate preparation (31.2 ± 6.5 vs 29.8 ± 5.9, respectively; P < .0001) and Charlson comorbidity scores (1.5 ± 1.6 vs 1.1 ± 1.4; P < .0001). Independent risk factors for inadequate preparation were a BMI of 30 kg/m(2) or greater (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.21-1.75; P < .0001), use of tobacco (OR, 1.28; 95% CI, 1.07-1.54; P = .0084) or narcotics (OR, 1.28; 95% CI, 1.04-1.57; P = .0179), hypertension (OR, 1.30; 95% CI, 1.07-1.57; P = .0085), diabetes (OR, 1.38; 95% CI, 1.12-1.69; P = .0021), and dementia (OR, 3.02; 95% CI, 1.22-7.49; P = .0169). CONCLUSIONS: BMI is an independent factor associated with inadequate split bowel preparation for colonoscopy. Additional factors associated with quality of bowel preparation include diabetes, hypertension, dementia, and use of tobacco and narcotics. Patients with BMIs of 30 kg/m(2) or greater should be considered for more intensive preparation regimens.Item Avoiding Bad Control in Regression for Partially Qualitative Outcomes, and Correcting for Endogeneity Bias in Two-Part Models: Causal Inference from the Potential Outcomes Perspective(2021-05) Asfaw, Daniel Abebe; Terza, Joseph; Ottoni-Wilhelm, Mark; Tennekoon, Vidhura; Tan, FeiThe general potential outcomes framework (GPOF) is an essential structure that facilitates clear and coherent specification, identification, and estimation of causal effects. This dissertation utilizes and extends the GPOF, to specify, identify, and estimate causally interpretable (CI) effect parameter (EP) for an outcome of interest that manifests as either a value in a specified subset of the real line or a qualitative event -- a partially qualitative outcome (PQO). The limitations of the conventional GPOF for casting a regression model for a PQO is discussed. The GPOF is only capable of delivering an EP that is subject to a bias due to bad control. The dissertation proposes an outcome measure that maintains all of the essential features of a PQO that is entirely real-valued and is not subject to the bad control critique; the P-weighted outcome – the outcome weighted by the probability that it manifests as a quantitative (real) value. I detail a regression-based estimation method for such EP and, using simulated data, demonstrate its implementation and validate its consistency for the targeted EP. The practicality of the proposed approach is demonstrated by estimating the causal effect of a fully effective policy that bans pregnant women from smoking during pregnancy on a new measure of birth weight. The dissertation also proposes a Generalized Control Function (GCF) approach for modeling and estimating a CI parameter in the context of a fully parametric two-part model (2PM) for a continuous outcome in which the causal variable of interest is continuous and endogenous. The proposed approach is cast within the GPOF. Given a fully parametric specification for the causal variable and under regular Instrumental Variables (IV) assumptions, the approach is shown to satisfy the conditional independence assumption that is often difficult to hold under alternative approaches. Using simulated data, a full information maximum likelihood (FIML) estimator is derived for estimating the “deep” parameters of the model. The Average Incremental Effect (AIE) estimator based on these deep parameter estimates is shown to outperform other conventional estimators. I apply the method for estimating the medical care cost of obesity in youth in the US.Item BMI, leisure-time physical activity, and physical fitness in adults in China: results from a series of national surveys, 2000–14(Elsevier, 2016-06) Tian, Ye; Jiang, Chongmin; Wang, Mei; Cai, Rui; Zhang, Yanfeng; He, Zihong; Wang, Huan; Wu, Dongming; Wang, Fubaihui; Tang, Qiang; Yang, Yang; Zhao, Jin; Lv, Shaojun; Zhou, Weihai; Yu, Bo; Lan, Jiang; Yang, Xinping; Zhang, Linxia; Tian, Hui; Gu, Zhuangzhuang; Song, Yiqing; Huang, Tianyi; McNaughton, Lars R.; Department of Epidemiology, Richard M. Fairbanks School of Public HealthBackground Obesity, physical inactivity, and reduced physical fitness contribute to the rising burden of chronic diseases in China. We investigated these factors in Chinese adults over a 14-year period (2000–14) using data from randomised national surveys. Methods We did four national surveys in 2000, 2005, 2010, and 2014 among Chinese adults aged 20–59 years. We used BMI to assess underweight (<18·5 kg/m2), overweight (≥23·0 to <27·5 kg/m2), and obesity (≥27·5 kg/m2). Central obesity was defined as a waist circumference greater than 90 cm in men and greater than 85 cm in women. We assessed leisure-time physical activity (LTPA) by whether or not participants had completed the recommended minimum 150 min of moderate or 75 min of vigorous exercise per week. Indices for assessment of physical fitness were forced vital capacity, resting heart rate, hand grip strength, sit and reach distance, and time standing on one leg. Findings 151 656 (78%) of 193 440 adults responded to the survey in 2000, 163 386 (84%) in 2005, 154 931 (80%) in 2010, and 146 703 (76%) in 2014. The prevalence of obesity increased from 8·6% in 2000, to 10·3% in 2005, 12·2% in 2010, and 12·9% in 2014 (estimated increase 0·32% per year, 95% CI 0·30–0·33; p<0·0001). The equivalent estimates were 37·4%, 39·2%, 40·7%, and 41·2% for overweight (estimated increase 0·27% per year, 95% CI 0·25–0·30; p<0·0001) and 13·9%, 18·3%, 22·1%, and 24·9% for central obesity (estimated increase 0·78% per year, 0·76–0·80; p<0·0001). The prevalence of overweight, obesity, and central obesity increased with age (all p<0·0001) and was higher in men than in women (all p<0·0001). We noted a simultaneous decrease in the prevalence of underweight (estimated decrease of 0·06% per year, 95% CI 0·04–0·07; p<0·0001). The proportion of adults meeting the minimum LTPA recommendation increased over time (17·2% in 2000, 18·1% in 2005, and 22·8% in 2014), with the estimated prevalence change per year being 0·33% (95% CI 0·24–0·42; p<0·0001) for underweight people, 0·50% (0·47–0·53; p<0·0001) for normal-weight people, 0·37% (0·34–0·40; p<0·0001) for overweight people, and 0·06% (0·00–0·13; p=0·044) for obese people. We noted deteriorations over time in all measures of physical fitness in normal-weight adults (all p<0·0001), apart from resting heart rate (p=0·69). Interpretation Despite increased participation in LTPA, we noted increases in overweight or obesity and a decrease in physical fitness in Chinese adults. Continued nationwide interventions are needed to promote physical activity and other healthy lifestyle behaviours in China.Item Body mass index is negatively associated with telomere length: a collaborative cross-sectional meta-analysis of 87 observational studies(Oxford University Press, 2018-09) Gielen, Marij; Hageman, Geja J.; Antoniou, Evangelia E.; Nordfjall, Katarina; Mangino, Massimo; Balasubramanyam, Muthuswamy; de Meyer, Tim; Hendricks, Audrey E.; Giltay, Erik J.; Hunt, Steven C.; Nettleton, Jennifer A.; Salpea, Klelia D.; Diaz, Vanessa A.; Farzaneh-Far, Ramin; Atzmon, Gil; Harris, Sarah E.; Hou, Lifang; Gilley, David; Hovatta, Iiris; Kark, Jeremy D.; Nassar, Hisham; Kurz, David J.; Mather, Karen A.; Willeit, Peter; Zheng, Yun-Ling; Pavanello, Sofia; Demerath, Ellen W.; Rode, Line; Bunout, Daniel; Steptoe, Andrew; Boardman, Lisa; Marti, Amelia; Needham, Belinda; Zheng, Wei; Ramsey-Goldman, Rosalind; Pellatt, Andrew J.; Kaprio, Jaakko; Hofmann, Jonathan N.; Gieger, Christian; Paolisso, Giuseppe; Hjelmborg, Jacob B. H.; Mirabello, Lisa; Seeman, Teresa; Wong, Jason; van der Harst, Pim; Broer, Linda; Kronenberg, Florian; Kollerits, Barbara; Strandberg, Timo; Eisenberg, Dan T. A.; Duggan, Catherine; Verhoeven, Josine E.; Schaakxs, Roxanne; Zannolli, Raffaela; dos Reis, Rosana M. R.; Charchar, Fadi J.; Tomaszewski, Maciej; Mons, Ute; Demuth, Ilja; Iglesias Molli, Andrea Elena; Cheng, Guo; Krasnienkov, Dmytro; D'Antono, Bianca; Kasielski, Marek; McDonnell, Barry J.; Ebstein, Richard Paul; Sundquist, Kristina; Pare, Guillaume; Chong, Michael; Zeegers, Maurice P.; Medical and Molecular Genetics, School of MedicineBackground: Even before the onset of age-related diseases, obesity might be a contributing factor to the cumulative burden of oxidative stress and chronic inflammation throughout the life course. Obesity may therefore contribute to accelerated shortening of telomeres. Consequently, obese persons are more likely to have shorter telomeres, but the association between body mass index (BMI) and leukocyte telomere length (TL) might differ across the life span and between ethnicities and sexes. Objective: A collaborative cross-sectional meta-analysis of observational studies was conducted to investigate the associations between BMI and TL across the life span. Design: Eighty-seven distinct study samples were included in the meta-analysis capturing data from 146,114 individuals. Study-specific age- and sex-adjusted regression coefficients were combined by using a random-effects model in which absolute [base pairs (bp)] and relative telomere to single-copy gene ratio (T/S ratio) TLs were regressed against BMI. Stratified analysis was performed by 3 age categories ("young": 18-60 y; "middle": 61-75 y; and "old": >75 y), sex, and ethnicity. Results: Each unit increase in BMI corresponded to a -3.99 bp (95% CI: -5.17, -2.81 bp) difference in TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -7.67 bp (95% CI: -10.03, -5.31 bp) difference. Each unit increase in BMI corresponded to a -1.58 × 10(-3) unit T/S ratio (0.16% decrease; 95% CI: -2.14 × 10(-3), -1.01 × 10(-3)) difference in age- and sex-adjusted relative TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -2.58 × 10(-3) unit T/S ratio (0.26% decrease; 95% CI: -3.92 × 10(-3), -1.25 × 10(-3)). The associations were predominantly for the white pooled population. No sex differences were observed. Conclusions: A higher BMI is associated with shorter telomeres, especially in younger individuals. The presently observed difference is not negligible. Meta-analyses of longitudinal studies evaluating change in body weight alongside change in TL are warranted.Item Decreased Quality of Life is Significantly Associated with Body Composition in Patients with Nonalcoholic Fatty Liver Disease(Elsevier, 2020) Samala, Niharika; Desai, Archita; Vilar, Eduardo; Smith, Emily R.; Gawrieh, Samer; Kettler, Carla D.; Pike, Francis; Chalasani, Naga; Medicine, School of MedicineBackground & Aims We studied impaired quality of life (QOL) and its determinants among individuals with nonalcoholic fatty liver disease (NAFLD). Methods We collected data from 341 patients with NAFLD who completed the short form 36 (SF-36) questionnaire. Body composition and liver fibrosis were assessed in patients with NAFLD using bioelectrical impedance and transient elastography, respectively. Advanced fibrosis was defined as liver stiffness measurements (LSMs) of 12.1 kPa or greater. SF-36 scores of patients with NAFLD were compared with SF36 scores of individuals with chronic medical illnesses and the general population obtained from the published literature. Results Among patients with NAFLD, percent body fat was negatively associated with scores from all 8 SF-36 scales, whereas lean body mass was positively associated with scores from 5 of 8 SF-36 scales. On multivariable analysis, SF-36 PF scores were negatively associated with type 2 diabetes, body mass index, and LSM and positively associated with lean body mass and level of alanine aminotransferase. Patients with NAFLD, and even those without advanced fibrosis, had significantly lower mean QOL scores than the control group or the general population. Conclusions Individuals with NAFLD, even those without advanced fibrosis, have lower QOL than controls. Body composition associates with QOL in patients with NAFLD; both of the modifiable factors independently associated with QOL are related to body composition. Further studies are needed to investigate if interventions to improve body composition can increase QOL for patients with NAFLD.Item Does Body Mass Index Modify Memory, Reasoning, and Speed of Processing Training Effects in Older Adults(Wiley, 2016-11) Clark, Daniel O.; Xu, Huiping; Callahan, Christopher M.; Unverzagt, Frederick W.; Medicine, School of MedicineObjective To describe 10-year trajectories of cognitive performance by body mass index (BMI) class and to investigate BMI differences in response to memory, reasoning, and speed of processing training in older adults. Methods This is a secondary analysis of the multisite, randomized trial Advanced Cognitive Training for Independent and Vital Elderly. There were 701 older adults with normal weight, 1,081 with overweight, and 902 with obesity (mean age 73.6) randomized to memory training, reasoning training, speed of processing training, or no-training control group. Participants completed memory, reasoning, and speed of processing tests. Baseline sociodemographic, health, and chronic disease measures were included as covariates in analyses. Results The 10-year trajectories of memory, reasoning, or speed of processing performance did not differ by BMI status among the participants randomized to the untrained control arm. The training effect on the reasoning and speed of processing outcomes did not differ by BMI status. The training effect on the memory outcome in participants with a BMI indicating obesity, however, was just 38% of that observed in participants with normal-weight BMI. Conclusions These analyses of data from the largest trial of cognitive training ever conducted suggest that older adults with obesity may be less responsive to memory training.Item Effect of Depression Treatment on Somatic Depressive Symptoms and Cardiometabolic Biomarkers among People without Diabetes(2022-05) Shell, Aubrey Lynn; Stewart, Jesse; Hirsh, Adam; Cyders, Melissa; Considine, RobertWhile depression is a risk factor for type 2 diabetes, little is known about the effect of depression treatment on diabetes risk markers. Using data from the recently completed eIMPACT trial (NCT02458690, supported by R01 HL122245), I examined if depression intervention improves diabetes risk markers and if improvements in somatic depressive symptoms mediate potential intervention effects. 216 participants (primary care patients ≥50 years with depression and elevated cardiovascular disease risk from a safety net healthcare system) were randomized to 12 months of the eIMPACT intervention (modernized collaborative care intervention involving internet cognitive-behavioral therapy [CBT], telephonic CBT, and/or select antidepressants; n=107) or usual primary care for depression (primary care providers supported by embedded behavioral health clinicians and affiliated psychiatrists; n = 109). Given my focus on diabetes risk, I excluded participants who did not attend the post-treatment visit (n = 17) or who had a diabetes history at pre-treatment (n = 73), leaving a final sample of 126 (n=66 intervention, n=60 usual care; Mage = 58 years, 79% women, 50% Black, 47% with income <$10k/year). I computed depressive symptom severity variables from the Hopkins Symptom Checklist-20 (SCL-20) items: hyperphagia (“overeating” item), poor appetite (“poor appetite”), hypersomnia (“sleeping too much”), disturbed sleep (“sleep that is restless or disturbed”) and SCL-15 (mean of items not pertaining to appetite or sleep). I calculated insulin resistance from fasting plasma glucose and insulin using the Homeostasis Model Assessment for Insulin Resistance (HOMA-IR)-2 calculator, body mass index (BMI) from measured height and weight, and plasma concentrations of high-sensitivity C-reactive protein (hsCRP), leptin, and ghrelin using ELISA kits. Parallel mediation analyses revealed that 12 months of modernized collaborative care for depression improved both directions of sleep symptoms but did not improve poor appetite or hyperphagia – the somatic symptom most consistently linked with increases in HOMA-IR, BMI, hsCRP, and leptin. Of the five cardiometabolic biomarkers examined, the eIMPACT intervention decreased only hsCRP and ghrelin. There were no intervention effects on HOMA-IR, BMI, or leptin. In addition, no somatic depressive symptoms mediated intervention effects on the cardiometabolic biomarkers, nor did race moderate any mediation effects. Further research is warranted to determine best practices for targeting hyperphagia and reducing cardiometabolic disease risk among people with depression.Item Evaluation of a Participant Co-designed Lifestyle Change Program for Youth(2022-05) Alharbi, Basmah Saleh; Perkins, Susan M.; Hannon, Tamara S.; Daggy, Joanne K.Introduction: Increasing obesity in children leads to an increase in the risk of Type 2 diabetes (T2D). Therefore, it is important to promote healthier lifestyles in youths and encourage their caregivers(s) to provide a healthy lifestyle environment. The PowerHouse program focuses on improving food choices, increasing physical activity, and adopting behavior changes for the reduction of obesity and the prevention of T2D. Method: The aim of this study was to assess the effects of implementing the PowerHouse program on both clinical and quality of life outcomes in high-risk, low-income youth and their caregivers. Primary outcomes were BMI standard deviation and BMI percentile in youths. Secondary outcomes included physical activity of youths and quality of life for both youths and their caregivers. Attendance rates were also calculated. Linear effect mixed models were used to test for time effects for all outcomes. Results: Clinical outcomes did not improve over time, except for youth HbA1c (p-value = 0.0447). Some improvements in youth quality-of-life outcomes were noted: specifically, the Sports Index score of the Fels Physical Activity Questionnaire for Children (adjusted p-value = 0.0213) and the Physical Summary (p-value = 0.0407), Psychosocial Summary (p-value = 0.0167), and Total score (p-value = 0.0094) for the youth-reported Pediatric Quality of Life Inventory. Quality of life did not change over time for caregivers. For attendance, there was an improvement after the intervention was modified to improve access to fresh produce (p-value = 0.0002). Conclusion: HbA1c and quality of life improved over time for youth; however, there was not an improvement in caregiver outcomes over time. The data suggest that more time may be needed to see the full effects of the intervention, and/or that a booster intervention may be needed.Item Fat-free mass accounts for most of the variance in alcohol elimination rate in women(Wiley, 2023) Seyedsadjadi, Neda; Ramchandani, Vijay A.; Plawecki, Martin H.; Kosobud, Ann E. K.; O'Connor, Sean; Rowitz, Blair; Pepino, Marta Yanina; Psychiatry, School of MedicineBackground: Understanding how blood alcohol concentrations (BAC) achieved after drinking are determined is critical to predicting alcohol exposure to the brain and other organs and alcohol's effects. However, predicting end-organ exposures is challenging, as there is wide variation in BAC achieved after drinking a specified volume of alcohol. This variation is partly due to differences in body composition and alcohol elimination rates (AER), but there are limited data on how obesity affects AER. Here, we assess associations between obesity, fat-free mass (FFM), and AER in women and examine whether bariatric surgeries, which are linked to an increased risk of alcohol misuse, affect these associations. Methods: We analyzed data from three studies that used similar intravenous alcohol clamping procedures to estimate AER in 143 women (21 to 64 years old) with a wide range of body mass index (BMI; 18.5 to 48.4 kg/m2 ). Body composition was measured in a subgroup using dual-energy X-ray absorptiometry (n = 42) or Bioimpedance (n = 60), and 19 of the women underwent bariatric surgery 2.1 ± 0.3 years before participation. We analyzed data using multiple linear regression analyses. Results: Obesity and older age were associated with a faster AER (BMI: rs = 0.70 and age: rs = 0.61, both p < 0.001). Compared to women with normal weight, AER was 52% faster (95% Confidence Interval: 42% to 61%) in women with obesity. However, BMI lost predictive value when adding fat-free mass (FFM) to the regression model. Age, FFM, and its interaction explained 72% of individual variance in AER (F (4, 97) = 64.3, p < 0.001). AER was faster in women with higher FFM, particularly women in the top tertile of age. After controlling for FFM and age, bariatric surgery was not associated with differences in AER (p = 0.74). Conclusions: Obesity is associated with a faster AER, but this association is mediated by an obesity-related increase in FFM, particularly in older women. Previous findings of a reduced alcohol clearance following bariatric surgery compared with prior to surgery are likely explained by a reduction in FFM post-surgery.