Effect of Short Bouts of Vigorous Stair Climbing on Cardiorespiratory Fitness in Women with Overweight and Obesity: A Pilot Feasibility Study.

Background: We examined the effect of 4 weeks of a brief vigorous stair climbing exercise on cardiorespiratory fitness (CRF) and body composition in women with overweight or obesity. Methods: Twenty-six participants (age, 25.4±4.9 years; body mass index [BMI], 25.3±1.8 kg/m2) were randomly assigned to either a stair climbing exercise group (n=13) or a non-exercising control group (n=13). The stair climbing exercise group performed 20 sessions (supervised, five sessions/week over 4 weeks) of brief intermittent stair climbing exercise consisting of a 3-minute warm-up followed by three bouts of 20 seconds of stair climbing (≥80% of age-predicted maximum heart rate) interspersed with 2-minute recovery periods (total exercise duration=10 minutes/session). Peak oxygen uptake (VO2peak) was measured using a graded maximal treadmill test with the use of a standard open-circuit spirometry technique. Body composition was assessed with bioelectrical impedance analysis. Results: All participants, except one who dropped out due to coronavirus disease 2019 (COVID-19) infection, completed the study with 100% attendance rates. There were significant interaction effects (group×time) on body weight, BMI, waist circumference, and CRF such that the stair climbing exercise group had significant (P≤0.01) reductions in body weight (66.5±4.6 to 65.2±4.6 kg), BMI (24.8±1.2 to 24.4±1.1 kg/m2), and waist circumference (78.0±3.7 to 76.5±4.1 cm) and improvements in VO2peak (31.6±2.5 to 34.9±2.6 mL/kg/min) compared with controls. Conclusion: Short bouts of vigorous stair climbing is a feasible and time-efficient exercise strategy for improving CRF in previously sedentary, young women with overweight and obesity.

Changes in the prevalence of U.S. adults using diet, exercise, pharmaceuticals and diet products for weight loss over time: Analysis of NHANES 1999-2018.

To examine changes in the use of diet, exercise, and pharmacological/diet product weight loss (WL) practices over time, and differences in these trends by sex and obesity status, data from the National Health and Examination Survey (NHANES Continuous 1999-2018) was used. The prevalence of diet, exercise and use of WL drugs and products over time were examined in men and women with and without obesity in a series of cross-sectional nationally representative samples (n = 43,020). Women and those with obesity were more likely to engage in WL practices over the past year, with an increased prevalence of WL efforts over time (38.4 to 43.2%). Amongst those who engaged in WL attempts, diet-related WL was most common (87-93%), followed by exercise-related WL (47-68%), whereas use of WL drugs and products was the least common (5-21%). There were modest differences in the prevalence of diet or exercise WL over time, with some differences by sex and obesity status. Most notable was the increase in the prevalence of exercise WL practices in women with obesity, with no differences among men or women without obesity. When examining specific types of diets, there were more clear differences in the adoption of diets over time, with the use of more traditional calorie/portion/fat restriction diets becoming less prevalent, and sugar/carbohydrate restriction becoming more prevalent over time (P<0.005). Changes over time in the use of diets were, were however, similar in men and women with and without obesity. Use of pharmacotherapy/diet products tended to decline in prevalence over time but was consistently highest in women with obesity. Thus, there are differences in the types of WL strategies individuals have employed over time, with variations in their popularity of use by sex and obesity status. However, the pattern of changes over time were quite similar in men and women with and without obesity.

Is anyone truly healthy? Trends in health risk factors prevalence and changes in their associations with all-cause mortality.

OBJECTIVE: The purpose of the study was to determine trends in the prevalence of individual health risk factors across time and to examine if their associations with mortality have changed over time. METHODS: Data from the National Health and Nutrition Examination Surveys (NHANES III- 1988-1994 and NHANES 1999-2014; age ≥20 years) was used to examine differences in the odds ratio (OR) of 5-year mortality risk associated with various common health risk factors over the two survey periods using weighted logistic regression analysis adjusting for age, sex, obesity category and white ethnicity (n = 28,279). RESULTS: Over 97% of individuals had at least one of the 19 risk factors examined with no difference in the prevalence over time (P>0.34). The prevalence of lifestyle, social/mental and physical risk factors (2.2 to 19.1%) increased over time (P<0.0002), while the prevalence of having physiological risk factors decreased by ~6.5% (P<0.0001). Having any lifestyle or social/mental risk factor was significantly associated with a higher 5-year OR for mortality risk in 1999-2014, than 1988-94. In particular, having low education or use of mental health medication were not associated with mortality risk in 1988-94 (P>0.1), but were significantly associated with a higher 5-year OR for mortality in 1999-2014 (P<0.0001). Conversely, physiological risk factors were more weakly related with mortality risk in 1988-1994, than 1999-2014. Having any physical risk factor, and poor self-rated health were similarly related with 5-year mortality risk at both timepoints. CONCLUSION: Health risk factors have both increased and decreased in prevalence over time, along with changes in the association between many of the risk factors and mortality risk. Taken together, these changes complicate interpretation of temporal trends and warrant cautious interpretation of population health patterns based on surveillance data.

Anthropometric Equations to Predict Visceral Adipose Tissue in European and American Youth.

OBJECTIVE: To investigate whether prediction equations including a limited but selected number of anthropometrics that consider differences in subcutaneous abdominal adipose tissue may improve prediction of the visceral adipose tissue (VAT) in youth. STUDY DESIGN: Anthropometrics and abdominal adipose tissue by MRI were available in 7-18 years old youth with overweight or obesity: 181 White Europeans and 186 White and Black Americans. Multivariable regressions were performed to develop and validate the VAT anthropometric predictive equations in a cross-sectional study. RESULTS: A model with both waist circumference (WaistC) and hip circumference (HipC) (VAT = [1.594 × WaistC] - [0.681 × HipC] + [1.74 × Age] - 48.95) more strongly predicted VAT in girls of White European ethnicity (R2 = 50.8%; standard error of the estimate [SEE] = 13.47 cm2), White American ethnicity (R2 = 41.9%; SEE, 15.63 cm2), and Black American ethnicity (R2 = 25.1%; SEE, 16.34 cm2) (P < .001), than WaistC or BMI. In boys, WaistC was the strongest predictor of VAT; HipC did not significantly improve VAT prediction. CONCLUSIONS: A model including both WaistC and HipC that considers differences in subcutaneous abdominal adipose tissue more accurately predicts VAT in girls and is superior to commonly measured anthropometrics used individually. In boys, other anthropometric measures did not significantly contribute to the prediction of VAT beyond WaistC alone. This demonstrates that selected anthropometric predictive equations for VAT can be an accessible, cost-effective alternative to imaging methods that can be used in both clinics and research.

Association between weight-loss history and weight loss achieved in clinical obesity management: Retrospective chart review.

OBJECTIVE: Weight history and its association with the weight loss achieved in a publicly funded clinical obesity management program were examined in 9348 patients. METHODS: Weight history (frequency and magnitude of weight losses) was collected through questionnaires at enrollment, and weight change was assessed with retrospective electronic medical chart review. RESULTS: The majority of patients reported developing overweight prior to the age of 40 years and having lost at least 4.5 kg (10 lb) of weight at least once in their lifetime. Those who had an earlier onset of overweight had a higher frequency of past weight loss and had more cumulative weight loss over their lifetime. In women, but not men, earlier age of overweight onset and lifetime weight loss were associated with modestly greater weight loss at the clinic. CONCLUSIONS: Women with greater weight-loss history also have modestly greater weight loss at the obesity management clinic. Thus, successful long-term obesity management, particularly for women, may include a series of repeated attempts at weight loss that should not be viewed as failures but could be viewed instead as practice.

The association of objectively and subjectively measured physical activity and sedentary time with prediabetes and type 2 diabetes in adults: a cross-sectional study in Framingham Heart Study cohorts.

The purpose of this study was to examine whether using both objectively (accelerometer) and subjectively (questionnaire) measured moderate- to vigorous-intensity physical activity (MVPA) and sedentary time (SED) improves the prediction of prediabetes and type 2 diabetes (pre/T2D) using data from the Framingham Heart Study (n = 4200). Logistic regression was used to examine the odds ratio of pre/T2D in groups cross-classified by subjective and objective MVPA and SED. Less than half of participants fell into concordant categories of MVPA and SED using subjective and objective measures, with 7.0%-9.4% of participants in the extreme discordant categories of high-low or low-high subjective-objective MVPA or SED. Low objective MVPA, regardless of subjective MVPA status, was associated with a higher prevalence of pre/T2D (P < 0.05). When cross-classifying by MVPA and SED, the majority of participants fell into concordant categories of MVPA-SED, with <4% of participants in the extreme discordant categories of MVPA-SED. Low objective MVPA, regardless of objective SED, was associated with a higher prevalence of pre/T2D (P < 0.05). These findings suggest that low objectively measured MVPA appears more closely associated with pre/T2D risk compared with subjective measures, and there does not appear to be an additive effect of SED on pre/T2D risk after accounting for MVPA.

Associations between weight discrimination and metabolic health: A cross sectional analysis of middle aged adults.

BACKGROUND: Concurrent with the recent rise in overweight and obesity, concerns with weight discrimination have arisen. Individuals who have experienced weight discrimination report a host of deteriorations related to physical and psychological health, which may co-exist with behaviours such as increased food consumption and decreases in physical activity that make weight management difficult. What remains less clear, however, is the extent to which metabolic health may be specifically affected, and how this may vary by setting and perceived intensity of the lifetime history of weight discrimination. METHOD: To address this, a secondary data analysis was performed on 1365 participants from year 25 of the Coronary Artery Disease in Young Adults (CARDIA) study who were living with overweight and obesity. Descriptive statistics and logistic regression analyses were performed on the presence of metabolic syndrome, diabetes, and abdominal obesity, as well as their experience of the weight discrimination. RESULTS: Prevalence of the metabolic syndrome, diabetes, and abdominal obesity was higher among those reporting low and high stress weight discrimination compared to those with no history of weight discrimination. In the adjusted analyses, weight discrimination was associated with a 65% greater likelihood for having metabolic syndrome, 85% greater likelihood of diabetes, and between a 2.5- and 3.9-times greater likelihood of abdominal obesity for low and high stress experiences, respectively. CONCLUSION: Exposure to weight discrimination may worsen metabolic health, as characterized by higher rates of metabolic syndrome and abdominal obesity. These associations may be greater with levels of stress experienced from weight discrimination. Further longitudinal work is necessary to understand the temporal sequence, time lag, and any possible critical periods for weight discrimination on metabolic health.

Predictors of Weight Loss and Weight Gain in Weight Management Patients during the COVID-19 Pandemic.

Objective: To examine the associations between patient struggles, health, and weight management changes during the COVID-19 pandemic. Methods: 585 patients attending a publicly funded clinical weight management program responded to an electronic survey. Results: Over half of the patients reported worsened overall health, mental health, physical activity, or diet during the pandemic. Approximately 30% of patients lost ≥3% of their body weight and 21% gained ≥3% of their body weight between March and July of the pandemic. Reports of social isolation was associated with increased odds for weight loss in women (OR = 2.0, 1.2-3.3), while low motivation (OR = 1.9, 1.0-3.7), depression (OR = 2.5, 1.0-6.3), and struggles with carbohydrate intake (OR = 2.1, 1.0-4.3) were associated with weight gain. Cooking more at home/eating less take out was associated with increased likelihood of weight loss (OR = 2.1, 1.1-3.9) and lower odds for weight gain (OR = 0.2, 0.1 to 0.97). Working from home was not associated with weight loss or weight gain (P > 0.6). Conclusion: The COVID-19 pandemic is associated with certain factors that may facilitate weight loss and other factors that promote weight gain. Thus, depending on the patient experience during the pandemic, prevention of weight gain may be more appropriate than weight loss.

The Associations between Blood and Urinary Concentrations of Metal Metabolites, Obesity, Hypertension, Type 2 Diabetes, and Dyslipidemia among US Adults: NHANES 1999-2016.

Background: Heavy metals are well known to be associated with cancer outcomes, but its association with obesity and cardiometabolic risk outcomes requires further study. Methods: Adult data from the National Health and Examination Survey (NHANES Continuous 1999-2016, n = 12,636 to 32,012) with data for blood or urinary metals concentrations and body mass index were used. The study aim was twofold: (1) to determine the association between heavy metals and obesity and (2) to examine the influence of heavy metals on the relationship between obesity and hypertension, type 2 diabetes, and dyslipidemia. Logistic regression was used to examine the main effects and interaction effects of metals and obesity for the odds of prevalent hypertension, type 2 diabetes, and dyslipidemia. Models were adjusted for age, gender, ethnicity, smoking status, physical active status, and poverty-income ratio, with additional adjustment for creatinine in models with the urinary measures of heavy metals. High-low concentration categories were defined by grouping metal quintiles with the most similar associations with obesity. Results: Blood lead had a negative linear association with obesity (odds ratio (OR) = 0.42, 95% confidence interval (CI) = 0.37-0.47). In those with obesity, high blood lead was associated with lower risk of prevalent dyslipidemia, while no association was found in those without obesity. The study observed a curvilinear relationship between urinary antimony and obesity with the moderate group having the highest odds of obesity (OR = 1.36, 1.16-1.59). However, the relationship between urinary antimony and prevalent hypertension and dyslipidemia risk was linear, positive, and independent of obesity. While not associated with prevalent obesity risk, high urinary uranium was associated with 30% (P=0.01) higher odds for prevalent type 2 diabetes. Conclusions: The impact of environmental factors on obesity and health may be complex, and this study reinforces the heterogeneous relationship between various metals, obesity, and obesity-related metabolic diseases even at levels observed in the general population.

Sequential diets and weight loss: Including a low-carbohydrate high-fat diet with and without time-restricted feeding.

OBJECTIVE: The aims of this study were to assess the effectiveness of a low-carbohydrate high-fat (LCHF) diet with and without a time-restricted feeding (TRF) protocol on weight loss and participating in three sequential dietary interventions (standard calorie-deficit diet, LCHF, and LCHF + TRF) on weight loss outcomes. METHODS: Data from 227 adults from the Wharton Medical Clinic (WMC) were analyzed using a unidirectional case crossover design. Data was imputed for 154 patients to create a pseudo-sample in which everyone participated in three dietary interventions: standard calorie restriction, LCHF, and LCHF + TRF. RESULTS: Patients lost an average of 11.1 ± 1.3 kg (9.8 ± 1.1%) after three sequential dietary interventions (P < 0.0001). Patients lost a statistically significant amount of weight from the standard WMC, LCHF, and LCHF+TRF diets (P < 0.05). With and without adjustment for age, sex, body mass index at the start of the dietary protocol, and treatment time, patients lost a similar amount of weight regardless of the dietary intervention (P > 0.05). Approximately 78.6% of patients achieved ≥5% weight loss with at least one of the diets. CONCLUSION: Patients can lose a similar amount of weight regardless of the diet they are following. Approximately 78.9% of patients achieved 5% weight loss with at least one of the diets and lost an average 11.1 kg (or 9.8%). This is nearly double what has been previously reported for one dietary intervention. Thus, participating in sequential diets may be associated with greater absolute weight loss, and likelihood of achieving a clinically significant weight loss.

Associations between elevated kidney and liver biomarker ratios, metabolic syndrome and all-cause and coronary heart disease (CHD) mortality: analysis of the U.S. National Health and Nutrition Examination Survey (NHANES).

BACKGROUND: We examined the relationship between ratios of select biomarkers of kidney and liver function on all-cause and coronary heart disease (CHD) mortality, both in isolation, and in combination with metabolic syndrome (MetS), among adults (20 + years, n = 10,604). METHODS: Data was derived from the U.S. National Health and Nutrition Examination Survey (1999-2016) including public-use linked mortality follow-up files through December 31, 2015. RESULTS: Select biomarker ratios of kidney (UACR or albuminuria and BUN-CR) and liver (AST-ALT and GGT-ALP) function in isolation and in combination with MetS were associated with all-cause and CHD mortality. Compared to individuals with neither elevated biomarker ratios nor MetS (HR = 1.00, referent), increased risk of all-cause mortality was observed in the following groups: MetS with elevated UACR (HR, 95% CI = 2.57, 1.99-3.33), MetS with elevated AST-ALT (HR = 2.22, 1.61-3.07), elevated UACR without MetS (HR = 2.12, 1.65-2.72), and elevated AST-ALT without MetS (HR = 1.71, 1.35-2.18); no other biomarker ratios were associated with all-cause mortality. For cause-specific deaths, elevated risk of CHD mortality was associated with MetS with elevated UACR (HR = 1.67, 1.05-2.67), MetS with elevated AST-ALT (HR = 2.80, 1.62-4.86), and elevated BUN-CR without MetS (HR = 2.12, 1.12-4.04); no other biomarker ratios were associated with CHD mortality. CONCLUSION: Future longitudinal studies are necessary to examine the utility of these biomarker ratios in risk stratification for chronic disease management.

The association of sex and calendar month with changes in weight: A retrospective cohort study of a community-based weight management clinic.

OBJECTIVE: To assess changes in weight by calendar month and sex in patients enrolled in a weight loss intervention. METHODS: Adults participating in a lifestyle weight loss intervention at the Wharton Medical Clinic from January 1st, 2007 to July 4th, 2019 were examined (N = 19,153). A linear generalized estimating equation was used to examine the association between weight change (baseline, month 1, month 2) and calendar month with adjustment for age, sex and baseline body mass index. A first order interaction between sex and calendar was included to assess if the association between calendar month and weight loss differs by sex. RESULTS: Patients lost 1.3 ± 2.0 kg (1.2 ± 1.8%) of their body weight per month. As compared to the mean monthly weight loss, patients lost slightly less weight in September (mean, 95% confidence interval (CI): -0.3, -0.4 to -0.2 kg) and slightly more weight in October (0.2, 0.1-0.3 kg). With adjustment for age, body mass index and calendar month, men lost 0.4 kg/month (95% CI: 0.3, 0.5 kg/month) than women. There were no other significant differences in the monthly weight change between men and women (sex*calendar month P-value = 0.24). CONCLUSION: While there were slight differences in the amount of weight change achieved by patients in September, and October, it was not of a magnitude that is likely clinically relevant. In addition, men consistently lost more weight than women across all calendar months. Taken together, this suggest that calendar month is not associated with differences in weight loss for men and women enrolled in a structured weight management program.

Association between metformin and physical activity with glucose control in adults with type 2 diabetes.

Objective: To examine the combined association between metformin use and physical activity on HbA1c in adults with type 2 diabetes. Research Design and Methods: Adults with type 2 diabetes from NHANES continuous survey (1999-2018, n = 6447) were classified as active and inactive based on self-reported engagement in moderate-to-vigorous or vigorous physical activity (MVPA or VigPA) and metformin use over the last month. Results: There was a significant negative main effect of metformin usage on HbA1c levels, independent of whether individuals engaged in modest levels of MVPA or VigPA. Moreover, there was a higher prevalence of metformin users with a HbA1c < 6.5% than non-metformin users with no differences by activity status (36.1%-39.5% versus 24.9%-29.7%, respectively). There was a significantly lower HbA1c level (P = .007) and trend for a higher odds of having a HbA1c that achieved the clinical target of <7% (OR, 95% CI = 1.2, 1.0-1.4, P = .06) in the MVPA than non-MVPA group for only those not using metformin. For those using metformin, there was no difference in HbA1c levels by either MVPA or VigPA (both P > .05). Conclusions: There appears to be independent benefits of metformin and regular physical activity on glucose control, but the impact of these two treatments are not necessarily additive. Based on this analyses, the benefit of physical activity on HbA1c levels in type 2 diabetes is likely more apparent in those not taking metformin, as compared to those who are.

An analysis of weight loss efforts and expectations in a Canadian Cohort: A retrospective medical chart review.

The weight loss history and weight loss goals were examined in 4108 patients referred to a publicly funded evidence-based clinical weight management program using a retrospective chart review. The majority of patients were white females, aged of 50.1 ± 13.7 years and a BMI of 39.0 ± 7.5 kg/m2 . Pregnancy was the most common reason for weight gain in women (17.7%) and while the reasons in men are more varied (injury, stress and medication: all ~5%). Over 50% of patients cited no specific reason for their weight gain. Self-directed diet and exercise were the most commonly used self-reported weight loss methods. Women were more likely to report using medication and bariatric surgical weight loss methods than men (P < .05), and only 5% of women and 12.8% men report never having tried to lose weight in the past. Patients had an ideal weight loss goal of 28.9% to 34.4%, which was similar to the patient's lowest reported adult weight. Approximately 70% of patients enrolling at the clinic had previously lost at least 4.5 kg (10 lb) one or more times and 16.7% lost weight at least 5 times in their life, but patient weight at enrolment was similar to their highest adult reported weight. Thus, most patients referred to this clinical weight management program have previously attempted self-directed diet and exercise weight loss. Patients were close to their highest adult weight and had very large weight loss goals, similar to what is typically achieved only by surgical intervention, despite having already had several bouts of weight loss.

Effects of Exercise on Resting Metabolic Rate in Adolescents with Overweight and Obesity.

Background: We examined the effects of exercise training on resting metabolic rate (RMR), and whether changes in body composition are associated with changes in RMR in adolescents with overweight and obesity. Methods: One hundred forty adolescents (12-18 years, BMI ≥85th percentile) participated in randomized exercise trials (3-6 months) at UPMC Children's Hospital of Pittsburgh (18 control, 51 aerobic, 50 resistance, and 21 combined aerobic and resistance exercise). All participants had RMR assessments by indirect calorimetry after a 10-12 hour overnight fast, and body composition by magnetic resonance imaging and dual-energy X-ray absorptiometry. Results: There were no significant changes in RMR (kcal/day) between exercise groups vs. controls (p > 0.05). All exercise groups decreased visceral fat (-0.2 ± 0.02 kg; p < 0.05) compared to control. Increases in fat-free mass (FFM) were only seen in the combined group (2.3 ± 0.4 kg; p < 0.05), whereas increases in skeletal muscle mass were observed in both resistance (1.2 ± 0.2 kg; p < 0.05) and combined (1.5 ± 0.3 kg; p < 0.05) groups vs. control. Change in FFM, but not fat mass (FM), visceral fat, or skeletal muscle mass (p > 0.05), was a significant determinant of changes in RMR, independent of exercise modality (p = 0.04). Conclusion: Although exercise modality was not associated with changes in RMR, change in FFM, but not skeletal muscle or FM, was a significant correlate of changes in RMR in adolescents with overweight and obesity. Clinicaltrials.gov registration numbers: NCT00739180, NCT01323088, NCT01938950.

No differences in the body fat after violating core bioelectrical impedance measurement assumptions.

OBJECTIVE: It is unclear to what degree acutely violating bioelectrical impedance analysis (BIA) measurement assumptions will alter the predicted percent fat mass (%FM) and whether this differs by sex or body mass index (BMI). METHODS: %FM was assessed under control, dehydration, exercise, water, food intake and non-voided bladder conditions with three BIA devices (Tanita: BC-418, TBF-314, & Omron HBF-306CN) for men (n = 23, age: 24.0 ± 5.2 years old) and women (n = 17, age: 22.5 ± 3.4 years old) separately. RESULTS: For all BIA devices, there were no differences in the %FM values between the control and the other conditions in men or women (- 1.9 to 0.4%, p > 0.05). Across the three devices and five conditions, 97% of %FM tests returned values within 5% of control (2 tests), and 86% of tests were within 2% of control despite violating an assumption. The errors were greatest with dehydration and women were more likely to have a %FM difference greater than 2% than men with dehydration using the hand-to-foot device (Tanita TBF-314: 59% versus 9%). There were no differences in %FM between control and the conditions when examined by BMI (overweight/obesity: - 2.8 to 0.1% and normal weight: - 1.7 to 0.5%; BMI*trial, p = 0.99). CONCLUSION: %FM estimates were similar despite acutely violating the preliminary measurement BIA assumptions across a range of different BMIs. The minor variations in %FM are smaller than what would be expected with day-to-day variability or weight loss intervention but may be larger in women than men.

Separate and combined relationships for cardiorespiratory fitness and muscular strength with visceral fat and insulin sensitivity in adolescents with obesity.

We examined the separate and combined associations for cardiorespiratory fitness (CRF) and muscular strength (MS) with total and regional fat, and insulin sensitivity (IS) in 204 adolescents (BMI ≥85th percentile, 12-18 years) at UPMC Children's Hospital of Pittsburgh. CRF was measured by maximum oxygen consumption during a graded treadmill test. MS was quantified by combining 1-repetition maximum test for the leg and bench press. Participants were stratified as having either high or low CRF and MS based on sex-specific median split. Both high CRF and high MS groups had lower (P < 0.05) total fat after adjustment for sex, Tanner stage and ethnicity than the low CRF and MS groups (Difference: 6.6, 2.6-9.6% and 5.4, 2.4-8.3%, respectively). High CRF, but not high MS, had lower visceral (67.5 versus 77.9 cm2, P < 0.01) and intermuscular fat (3.6 versus 4.0 kg, P = 0.01) than the low CRF groups. Differences by CRF remained significant after adjustment for MS. High CRF, but not high MS, was associated (P < 0.05) with lower fasting glucose and higher IS after accounting for sex, Tanner stage and ethnicity than the low CRF group, and high CRF remained associated with these markers after adjustment for MS. High CRF is associated with lower total and regional fat, and higher IS after adjustment for MS. Novelty: CRF is associated with lower total fat, visceral and intermuscular fat, and higher insulin sensitivity adjusting for muscular strength. Muscular strength is not associated with regional body fat and insulin sensitivity after accounting for CRF.

Assessing the utility of cardiorespiratory fitness, visceral fat, and liver fat in predicting changes in insulin sensitivity beyond simple changes in body weight after exercise training in adolescents.

To examine the utility of changes in cardiorespiratory fitness (CRF) and body composition in response to exercise training in adolescents with obesity beyond simple measures of body weight change. This is a secondary analysis of our previously published randomized trials of aerobic, resistance, and combined training. We included 104 adolescents (body mass index (BMI) ≥85th percentile) who had complete baseline and post-intervention data for CRF, regional body fat, insulin sensitivity, and oral glucose tolerance. Associations between changes in body composition and CRF with cardiometabolic variables were examined adjusted for age, sex, Tanner stage, race, exercise group, and weight loss. At baseline, CRF, visceral fat and liver fat were correlated with insulin sensitivity with and without adjustment for BMI percentile. Training-associated changes in CRF, visceral fat, and liver fat were also correlated with insulin sensitivity changes, but not independent of body weight change. After accounting for body weight change, none of the body composition or CRF were associated with changes in insulin sensitivity, glucose tolerance, systolic blood pressure, or high-density lipoprotein cholesterol. Although CRF and body composition were strong independent correlates of insulin sensitivity at baseline, changes in CRF and visceral fat were not associated with changes in insulin sensitivity after accounting for body weight change. Clinicaltrials.gov registration nos.: NCT00739180, NCT01323088, NCT01938950. Novelty With exercise training, changes in body weight, CRF, visceral fat, and liver fat were correlated with changes in insulin sensitivity. Changes in body composition or CRF generally did not remain significant correlates of changes in insulin sensitivity after adjusting for body weight changes.