Longitudinal body composition changes in old men and women: interrelationships with worsening disability

BACKGROUND: Few studies have evaluated prospectively age-related body composition changes and their relationships with worsening disability in the elderly population. METHODS: Ninety-seven women and 62 men aged 71.4+/-2.2 and 71.6+/-2.2 years, respectively, at baseline underwent dual-energy x-ray absorptiometry determinations at baseline and at 2- and 5.5-year follow-up intervals to measure total body and leg fat (FM) and total, appendicular, and leg fat-free mass (FFM). Height, weight, body mass index (BMI), and waist circumference (as well as reported disabilities using a four-level scale) were evaluated at baseline and at 2- and 5.5-year follow-up. RESULTS: In both sexes, total FM did not change significantly, while total, appendicular, and leg FFM significantly decreased over the study follow-up. In men and women losing weight, BMI, total and leg FM, and total, appendicular, and leg FFM significantly decreased. In weight-stable men and women, appendicular and leg FFM significantly decreased and BMI, waist circumference, and total FM significantly increased. Men lost significantly more total, appendicular, and leg FFM than did women, irrespective of whether they maintained or lost weight. Over the follow-up period, 43.3% of women and 43.5% of men declined in one or more levels of reported disability. We evaluated the effect of age, baseline BMI, FM, FFM, number of diseases, baseline 6-minute walking test, categories of weight change, total, appendicular, or leg FFM changes, total FM and waist changes on the probability of a decline in one or more levels of reported disability score over the follow-up period, taking into account sex. Patients losing appendicular and leg FFM were 2.15 and 2.53 times, respectively, more likely to report increased disability than were patients without FFM loss. CONCLUSIONS: Reduction in appendicular or leg FFM was the main predictor of decline in one or more levels of reported disability in older men and women, and accounted for about a 2-fold increase in risk.     

Does lipid oxidation differ in gynoid and android obese women?

This study was performed to investigate whether body fat distribution influences resting metabolic rate and lipid oxidation in obese individuals. Eighty-nine obese women were divided in two groups (android obese, n = 36, BMI = 31.1 +/- 4.5 kg/m2 (mean +/- s.d.); gynoid obese, n = 53, BMI = 29.9 +/- 4.5 kg/m2 on the basis of their waist/hip ratio (0.86 +/- 0.05 vs 0.75 +/- 0.04 respectively). Body weight, per cent body fat and fat-free mass were similar in the two groups. Moreover, resting metabolic rate and respiratory quotient were also identical in android and gynoid obese women, indicating that there was no intergroup difference in the absolute level of lipid oxidation. If, like most other android obese women, they had higher rates of lipolysis and plasma FFA concentrations, the failure of android obese individuals to exhibit a higher lipid oxidation than gynoid obese women may partly explain their increased risk to develop metabolic complications.     

Laparoscopic gastric banding and body composition in morbid obesity

BACKGROUND AND AIM: Gastric banding induced considerable and rapid weight loss in morbid obesity. Nevertheless data on changes in body composition following gastric banding are scanty. In this study, we evaluated the 2-year changes in body composition in a small group of morbidly obese women treated by laparoscopic adjustable gastric banding (LAGB) associated with a well balanced low-calorie diet. METHODS AND RESULTS: We studied 20 premenopausal morbid obese women with BMI ranging from 35 to 57 (kg/m2) before, and 6, 12 and 24 months after laparoscopic adjustable gastric banding (LAGB). A well balanced 5.4 MJ/day hypocaloric diet was prescribed after surgery. Total body water (TBW), fat-free mass (FFM) and fat mass (FM) were investigated using conventional bioelectrical impedance analysis (BIA). Tissue hydration was also assessed by impedance vector analysis and the RXc graph method. The subjects showed a total weight loss of 28% of baseline body weight. In the first 6 months after surgery, patients lost 18.5+/-5.9 kg of body weight (17.6+/-6.2 kg of FM and 0.7+/-1.4 kg of FFM). From 6 to 12 months, a further 12.5+/-7.5 kg of body weight was lost (10.5+/-8.2 kg of FM and 2.2+/-3.8 kg of FFM). During the last 12 months, weight loss was 3.0+/-2.3 kg (1.9+/-3.7 kg of FM and 1.1+/-2.9 kg of FFM). The weight loss observed after LAGB was mainly due to a decrease in FM, whereas TBW, FFM and BCM were only slightly and non-significantly reduced. No changes in body hydration status were observed after surgery. CONCLUSIONS: LAGB associated with a well balanced low-calorie diet achieved a satisfactory 2-year weight loss, while sparing FFM and not causing body fluid alterations.     

Intrapair resemblance in very low calorie diet-induced weight loss in female obese identical twins

OBJECTIVE: To assess intrapair resemblance in changes of body weight, total body fat, fat distribution, resting metabolic rate, fasting respiratory quotient and cardiovascular disease risk factors in response to therapeutic weight loss in female obese identical twins. DESIGN: Patients stayed for 40 days on an inpatient metabolic unit under careful supervision. The stay was divided into three parts: an initial period of 7 days for adjustment to the hospital environment and for baseline measurements, 28 days of the weight reduction regimen when negative energy balance was achieved mainly by a very low calorie diet (1.6 MJ per day) and 5 days of testing after weight reduction. SUBJECTS: Fourteen pairs of premenopausal female obese identical twins (age: 39.0+/-1.7 y; body weight (BW): 93.9+/-21.2 kg; body mass index (BMI): 34.2+/-7.8 kg/m2) participated in the study. MEASUREMENTS: Before and after weight loss, the following measurements were made: body composition by anthropometry and hydrodensitometry, intra-abdominal fat by ultrasonography, resting metabolic rate by indirect calorimetry. Total cholesterol, high-density lipoprotein-cholesterol, triglycerides and uric acid were determined by standard laboratory procedures. Blood pressure was measured in the morning in the recumbent position. RESULTS: Subjects lost 8.8+/-1.9 kg of weight, from 93.9+/-21.2 to 85.1+/-10.9 kg (P<0.0001) and 6.5+/-2.3 kg of body fat (P<0.001). Weight losses varied widely among subjects, with a high correlation between losses of members of twin pairs for body weight (r=0.85; P<0.001) and for body fat (r=0.88; P<0.0001). Changes in uric acid resulting from weight loss were also correlated among members of twin pairs whereas changes in blood pressure, cholesterol and triglycerides were not. CONCLUSION: The great intrapair resemblance observed in very low calorie diet-induced weight and fat losses in female obese identical twins suggests an important role of genetic factors in response to the weight reduction regimen.     

Importance of plasma leptin in predicting future weight gain in obese children: a two-and-a-half-year longitudinal study

OBJECTIVE: To determine whether relatively low leptin levels predict changes in adiposity in prepubertal and pubertal obese children. RESEARCH METHODS AND PROCEDURES: In a biracial cohort of 68 obese children (33 male and 35 female; 46 Caucasians and 22 African-Americans, age range 7-18 y), we measured at baseline fasting insulin and leptin levels, height and weight and calculated body mass index (kg/m(2)) and expressed body mass index as (BMI) Z-score. After a 2.5-y follow-up, anthropometric measurements were repeated and changes in weight gain were calculated as changes in BMI Z-score. RESULTS: At baseline obese preadolescent boys and girls had similar age and BMI Z-score, fasting insulin and leptin levels. After an average follow-up of 2.5 y, mean weight change calculated by changes in BMI Z-score from baseline was similar in both groups. In obese adolescent boys and girls at baseline, no significant gender differences were observed for BMI Z-score and insulin levels. In contrast, plasma leptin levels were significantly higher in obese girls compared with obese adolescent boys. At follow-up, there was no significant difference in change in BMI Z-score between obese boys and girls. Multiple linear regression analysis revealed that high basal leptin levels were positively associated with greater changes in BMI Z-score only in girls (r(2)=0.18, P<0.02), after adjusting for basal BMI Z-score, Tanner stage, years of follow-up and basal insulin. High basal leptin levels in girls explained 18% of the weight gain. CONCLUSION: High leptin levels are associated with excessive future weight gain only in girls.     

Self-efficacy in relation to eating behaviour among obese and non-obese women.

OBJECTIVE: To assess the effect of a 3 month behaviour modification weight management programme on self-efficacy and anthropometric variables among obese women seeking treatment at an obesity management clinic and to compare self-efficacy among these obese women to non-obese women. DESIGN: Cross sectional. SUBJECTS: A total of 161 non-obese (BMI 22.6+/-2.9 kg/m(2)) and 138 obese (BMI 37.7+/-5.8 kg/m(2)) women of similar age. MEASUREMENTS: Self-efficacy in relation to eating was assessed by the Weight Efficacy Lifestyle (WEL) questionnaire. Demographic information was obtained by interview and questionnaire in the obese and by questionnaire in the non-obese. Anthropometric measurements were obtained by direct measure in the obese and BMI was calculated from self-reported weight and height in the non-obese. RESULTS: At entry to the programme obese women scored significantly less (P<0.0001) than non-obese women on the WEL (99.4+/-34.1 vs 139.0+/-24.9). Women who completed the programme (n=65) demonstrated a decrease in waist circumference of 3.9+/-5.3 cm, a 10.0+/-11.5% loss of excess weight and a significant improvement in total WEL score from 106.0+/-30.3 to 126.5+/-28.4. CONCLUSION: Improvements in some dimensions of self-efficacy among obese women were of sufficient magnitude to attain scores similar to women of a normal weight. The WEL questionnaire may provide an additional measure of success as well as provide positive feedback and encouragement to the client.     

Weight loss without losing muscle mass in pre-obese and obese subjects induced by a high-soy-protein diet

OBJECTIVE: To determine change of weight, body composition, metabolic and hormonal parameters induced by different intervention protocols. DESIGN: Randomized, controlled study including participants exhibiting a BMI between 27.5 and 35. Three different interventions containing lifestyle education (LE-G), or a substitutional diet containing a high-soy-protein low-fat diet with (SD/PA-G) or without (SD-G) a guided physical activity program. SUBJECTS: A total of 90 subjects (mean weight 89.9 kg; mean BMI 31.5), randomly assigned to one of three treatment groups. MEASUREMENTS: Change in body weight, fat mass and lean body mass measured with the Bod Pod device at baseline, 6 weeks and 6 months; change in metabolic and hormonal parameters. RESULTS: In all, 83 subjects completed the 6-months study. BMI dropped highly significantly in all groups (LE-G: -2.2+/-1.43 kg/m(2); SD-G: -3.1+/-1.29 kg/m(2); SD/PA-G: -3.0+/-1.29 kg/m(2)). Subjects in the SD-G and in the SD/PA-G lost more weight during the 6-months study (-8.9+/-3.9; -8.9+/-3.9 kg) than did those in the LE-G (-6.2+/-4.2 kg), and had a greater decrease in fat mass (-8.8+/-4.27; -9.4+/-4.54 kg) than those in the LE-G (-6.6+/-4.59 kg). In contrast, no significant intraindividual or between-group changes in the fat-free mass were seen. In all groups, metabolic parameters showed an improvement in glycemic control and lipid profile. CONCLUSIONS: Our data suggest that a high-soy-protein and low-fat diet can improve the body composition in overweight and obese people, losing fat but preserving muscle mass.     

Changes in long-term glycemic control and performance indicators in a cohort of type 2 diabetic patients cared for by general practitioners: findings from the "Modena Diabetes Project"

BACKGROUND AND AIM: General practitioners (GPs) are being increasingly asked to play a key role in the shared care of people with diabetes mellitus, but data concerning the effects of this in Italy are still scarce. We therefore evaluated the 4-year follow-up changes in outcomes and performance indicators in type 2 diabetic patients cared for by GPs in the framework of the "Modena Diabetes Project". METHODS AND RESULTS: Seventy-four percent of the local GPs participating in the project (387 out of 521) sent 5260 paired baseline and follow-up datasheets. The baseline characteristics of the type 2 diabetic patients (49.6% male) were a mean age of 67.3+/-11.2 years, a mean disease duration of 10.9+/-7.4 years, a mean BMI of 28.7+/-4.8 kg/m2, and a mean HbA1c level 7.56+/-1.52%. After four years follow-up, the individual before/after match-paired outcomes revealed an improvement in glycemic control: HbA1c levels significantly decreased to 7.39+/-1.31%, and the percentage of patients with HbA1c level of <6.5% significantly increased from 15.7% to 22.1%. There was also a significant decrease in body weight (from 78.3+/-14.8 to 77.6+/-14.6 kg) and BMI (from 28.8+/-4.8 to 28.5+/-4.9 kg/m2). The time trends of glycemic control significantly improved during the 4-year follow up, but those of the body weight and BMI values did not. Furthermore, the percentages of performance indicators matching the expected rate of recurrence per each year of follow-up significantly improved during the study period. CONCLUSIONS: Long-term glycemic control and the performance indicators relating to the type 2 diabetic patients participating in our shared care programme progressively improved.     

Associations of leptin, insulin resistance and thyroid function with long-term weight loss in dieting obese men

OBJECTIVE: The aim of the present study was to identify predictors of weight loss in obese men participating in a 2-year behaviour modification programme. DESIGN: Longitudinal, clinical intervention study of a behaviour modifying weight loss program. SETTING: University Hospital, Stockholm, Sweden. SUBJECTS: Forty-four obese men (age, 42.7 +/- 1.1 years: BMI, 37.1 +/- 0.6 kg m(-2), mean +/- SEM) followed for 2 years. INTERVENTIONS: Behaviour modification weight loss programme. MAIN OUTCOME MEASURES: Associations between plasma leptin and thyroid function tests, insulin resistance by homeostatic model assessment (HOMA), dietary recall and anthropometrically determined body composition. RESULTS: At baseline, there were significant correlations between plasma leptin and body mass index (BMI), fat-free mass (FFM) and insulin resistance. Median weight loss over 2 years was 4.9 kg (range, -27.2 to +11.9). Baseline serum leptin concentrations adjusted for BMI (leptin/BMI ratio) were significantly correlated with 2-year weight change (r = 0.34, P = 0.04). A subset of seven of the 44 men gained weight over the 2 years. These 'gainers' differed significantly in initial leptin/BMI ratio (0.62 +/- 0.07) compared with the 37 'losers' (0.42 +/- 0.03, P < 0.05). In a multiple regression model, baseline leptin, insulin and age predicted 22% of the variance in weight change with no additional significant contribution from BMI, FFM, waist:hip ratio, thyroid function tests or energy intake. There was a strong correlation between the change in leptin concentrations and the change in insulin resistance from baseline to 2-year follow-up (r = 0.54; P < 0.001). CONCLUSION: Baseline plasma leptin concentrations predicted long-term weight loss. Inappropriate leptin secretion or disposal, corrected for BMI, was associated with failure to maintain weight loss in obese men in a behaviour modification weight loss programme.     

Weight gain and adipose tissue metabolism after smoking cessation in women

BACKGROUND: Cigarette smoking increases the risk of cardiovascular disease, and is an important preventable cause of death and illness. One major deterrent to smoking cessation is a gain in body weight. Understanding the mechanisms that contribute to this weight gain may maximize the success of long-term smoking cessation. We hypothesized that smoking cessation is associated with an increase in adipose tissue lipoprotein lipase (AT-LPL) activity and/or a decrease in lipolysis, two metabolic factors that determine the balance between fat storage and fat utilization, and thus affect the propensity for weight gain. MATERIALS AND METHODS: Ten premenopausal women (37.1+/-6.2 y, 31.7+/-6.4 kg/m(2) body mass index (BMI), mean+/-s.d.) participated in a 4 week smoking cessation program. Measurements of body weight, waist and hip circumferences, adipose cell metabolism and resting metabolic rate were obtained at baseline and after 4 weeks of smoking cessation. RESULTS: Of the 10 women who began the intervention, five successfully completed the smoking cessation intervention. After 4 weeks of smoking cessation, there were significant increases in body weight (95.1+/-13.9-97.7+/-14.4 kg, P<0.05), with no change in waist and hip circumferences or resting energy expenditure. Gluteal AT-LPL activity significantly increased in all women by 2.8-fold (1.65+/-1.30-4.72+/-3.34 nmol/g/min, P<0.05). Abdominal AT-LPL activity increased in four out of the five women, but did not reach statistical significance (1.14+/-0.88-3.50+/-3.76 nmol/g/min, P=0.14). The increase in body weight correlated with the increase in gluteal AT-LPL activity (r=0.89, P<0.05), as well as the baseline activity of gluteal AT-LPL (r=0.86, P=0.06). There were no changes in basal or stimulated lipolysis in the gluteal or abdominal fat depots. CONCLUSIONS: These results suggest that smoking cessation is associated with significant increases in body weight, as well as changes in adipose cell metabolism, in particular increases in AT-LPL activity. This increase in LPL activity may contribute to the increase in body weight associated with smoking cessation.     

Relationships between changes in weight and changes in cardiovascular risk factors in middle-aged French subjects: effect of dieting

OBJECTIVE: To investigate relationships between changes in weight and changes in cardiovascular risk factors in adults, taking intentionality of weight loss into account. DESIGN: Longitudinal study in middle-aged French subjects from the SU.VI.MAX cohort. SUBJECTS: A total of 1773 men (body mass index (BMI) 25.4+/-3.1 kg/m(2), mean+/-s.d) and 2316 women (BMI 23.3+/-3.8 kg/m(2)) aged 45 y and over at baseline. MEASUREMENTS: Weight, height, blood pressure, serum total cholesterol and fasting blood glucose were measured at baseline and after a 2 y follow-up. Self-reported dieting in order to lose weight, smoking status, leisure-time physical activity, health events and current treatments were assessed through questionnaires. RESULTS: In multivariate analyses, weight change was positively associated with changes in systolic and diastolic blood pressure (P=0.0002 in women, P=0.0001 in men) and with changes in serum total cholesterol (P=0.008 in women, P=0.02 in men), after adjustment for age, baseline level of each cardiovascular risk factor and current treatments. For example, in men, a weight loss of 5 kg was associated with a decrease of 2.5 mmHg in systolic blood pressure and of 1.5 mmHg in diastolic blood pressure. Taking into account self-reported dieting did not modify these associations. CONCLUSIONS: In both genders, systolic and diastolic blood pressure and serum cholesterol increased with weight gain and decreased with weight loss, independently of the intentionality to lose weight. At the population level, modest weight loss may have a substantial impact on cardiovascular risk, and preventing even modest weight gain in adults is an important goal in terms of public health.     

Age-related differences in metabolic adaptations following resistance training in women

The purpose of this study was to determine whether aging alters changes in resting metabolic rate, body composition and insulin sensitivity in response to resistance training (RT) in women. The impact of a 6-month controlled RT program on fat-free mass (FFM), resting energy expenditure (REE), and glucose disposal was examined in 19 younger (27.8+/-3.5 yr; range 18-35) and 12 older (66.6+/-4.9 yr, range 55-70) non-obese caucasian women. For younger women, the RT program increased body weight (59.1+/-6.2 to 60.8+/-6.1 kg, p<0.05) due to an increase in FFM (39.2+/-3.7-40.4+/-3.2 kg, p<0.05). REE increased from 1379+/-114 to 1451+/-140 kcal day(-1), p<0.0001), and glucose disposal (from 364.1+/-91.1 to 402.1+/-87.8 mg min(-1), p<0.05). Neither fat mass nor VO2max changed significantly. On the other hand, older women lost fat mass (24.0+/-4.6-23.2+/-5.4 kg, p<0.05) and tended to gain FFM (from 37.3+/-4.0-38.0+/-4.3 kg, +1.9%; p=0.057), whereas no change occurred in body weight, REE, VO(2)max or glucose disposal. Thus, younger women showed greater metabolic changes in body composition, REE and insulin sensitivity in response to RT than older women. These results suggest an age-related alteration in metabolic changes in response to a 6-month RT program in previously untrained women.     

Validity of the leg-to-leg bioimpedance to estimate changes in body fat during weight loss and regain in overweight women: a comparison with multi-compartment models

OBJECTIVES: To investigate changes in body composition and the validity of the leg-to-leg bioimpedance (LTL) method to measure body fat during active weight loss (WL) and weight regain (WR). DESIGN: Longitudinal, 12-week weight loss intervention (3.3-3.8 MJ/day) and subsequent follow-up at 1 year.Subjects:Fifty-eight adult women aged between 24 and 65 years (mean age: 46.8+/-8.9 years) and with a body mass index (BMI) > or =25 kg/m(2) (mean BMI: 31.6+/-2.5 kg/m(2), range=26.0-48.2 kg/m(2)) participated in the study. MEASUREMENTS: Fat mass (FM) was measured at baseline, 12 weeks, 24 weeks and 52 weeks using three- and four-compartment (4-C) models, air displacement plethysmography (ADP), deuterium dilution - total body water (TBW), dual-energy X-ray absorptiometry (DXA), skinfold thickness (SFT), tetrapolar bioelectrical impedance analysis (T-BIA) and LTL. RESULTS: At the end of the weight loss programme, subjects lost 9.9+/-3.5 kg weight (P<0.001) and 7.6+/-0.5 kg fat (P<0.001) but after 1 year they had regained 4.9+/-3.7 kg of weight and 3.7+/-2.9 kg of fat. The 4-C model showed that FM and TBW accounted for 76.2 and 23.6% of the loss in body mass and 81.8 and 17.7% of the tissue accrued during weight regain, respectively. The estimate of body fat change by LTL relative to multi-compartment models (WL(bias+/-2s.d.)=0.51+/-3.26 kg; WR(bias+/-2s.d.)=-0.25+/-2.30 kg) was similar to ADP, DXA and TBW in both phases but it was better than T-BIA (WL(bias+/-2s.d.)=0.17+/-7.90 kg; WR(bias+/-2s.d.)=-0.29+/-7.59 kg) and skinfold thickness (WL(bias+/-2s.d.)=2.68+/-6.68 kg; WR(bias+/-2s.d.)=-0.84+/-3.80 kg). CONCLUSIONS: Weight loss and regain were associated with minimal changes in lean tissue as measured using multi-compartment models. The LTL system is a useful method to measure body composition changes during clinical weight management programmes.     

Recent weight changes and weight cycling as predictors of subsequent two year weight change in a middle-aged cohort

OBJECTIVE: To evaluate the influence of recent weight changes (weight gain, loss and cycling) on subsequent weight changes. DESIGN: Prospective cohort study with 2 y of follow-up. Data analysis with a polytomous logistic regression model. SUBJECTS: A total of 18 001 non-smoking subjects, 6689 men and 11 312 women, from the general population. MEASUREMENTS: Body height and weight measurements and interview data on lifestyle habits and medical history at baseline. For follow-up, self-administered questionnaires for assessment of body weight and incident diseases. RESULTS: Recent changes in body weight, that is weight gain, weight loss and weight cycling, were significant predictors of subsequent weight changes in both men and women after controlling for age, baseline BMI and several lifestyle and behavioural characteristics as potential confounding factors. Weight cycling before baseline was the strongest predictor of subsequent large weight gain (> or =2 kg) with an odds ratio (OR) of 4.84 (95% confidence interval (CI) 3.34-7.02) in men. In women, prior weight loss was the strongest predictor of subsequent large weight gain (OR 4.77; 95% CI 3.63-6.03), followed by weight cycling (OR 3.02; 95% CI 2.15-4.25). CONCLUSION: These data indicate the need for thorough weight history assessment to identify those who are most likely to gain weight. Effective weight control before the development of obesity or after intentional weight loss due to obesity should be a primary goal in the management of obesity.     

Weight, weight change, mortality in a random sample of older community-dwelling women

OBJECTIVE: To evaluate the relationship between measured weight, weight change, and 6-year mortality risk in a random sample of 648 community-dwelling women aged 65 and older from Baltimore, Maryland. MEASUREMENTS: Data were collected using a standardized questionnaire and administered in person by trained interviewers. Questionnaires were completed annually from 1984 to 1986, and body weight was measured at each interview. Weight was defined as body mass index (BMI) of low (< 23 kg/m2), average (> or = 23 kg/m2 to < or = 28 kg/m2), and high (> 28 kg/m2). Four mutually exclusive categories of weight change of at least 4.5% in BMI over the three annual interviews were developed to describe all possible weight change patterns: weight gain, weight loss, no change, and weight cycling. RESULTS: During the follow-up period, 106 women (16%) died. Women with low baseline BMI, regardless of weight change, and those who lost weight, regardless of baseline BMI had increased mortality risk. Women with average baseline BMI and weight loss had a very high mortality risk (hazard ratio (HR) 3.84, 95% Confidence interval (CI) 2.14-6.89). Women who weight cycled had increased mortality risk at low and high baseline weights, and a nonsignificant increased risk at average baseline weight (P = .069). Analyses were adjusted for age, education, smoking, alcohol usage, and pre-existing illness and included an interaction between weight change and baseline BMI. CONCLUSIONS: These results suggest that white, older, community-dwelling women are at an increased risk of mortality if they are underweight, lose weight, or weight cycle.     

Plantar pressure differences between obese and non-obese adults: a biomechanical analysis.

OBJECTIVE: To investigate plantar pressure differences between obese and non-obese adults during standing and walking protocols using a pressure distribution platform. SUBJECTS: Thirty-five males (age 42.4+/-10.8 y; 67-179 kg) and 35 females (age 40.0+/-12.6 y; 46-150 kg) divided into obese (body mass index (BMI) 38.75+/-5.97 kg/m2) and non-obese (BMI 24.28+/-3.00 kg/m2) sub-groups, respectively. MEASUREMENTS: Data collection was performed with a capacitive pressure distribution platform with a resolution of 2 sensors/cm2 (Emed F01, Novel GmbH, München). The measurement protocol included half and full body weight standing on the left, right and both feet, respectively, and walking across the platform, striking with the right foot. Pressures were evaluated for eight anatomical sites under the feet. RESULTS: For both men and women, the mean pressure values of the obese were higher under all anatomical landmarks during half body weight standing. Significant increases in pressure were found under the heel, mid-foot and metatarsal heads II and IV for men and III and IV for women. Foot width during standing was also significantly increased in obese subjects. For walking, significantly higher peak pressures were also found in both obese males and females. CONCLUSION: Compared to a non-obese group, obese subjects showed increased forefoot width and higher plantar pressures during standing and walking. The greatest effect of body weight on higher peak pressures in the obese was found under the longitudinal arch of the foot and under the metatarsal heads. The higher pressures for obese women compared to obese men during static weight bearing (standing) may be the result of reduced strength of the ligaments of the foot.     

Fasting respiratory exchange ratio and resting metabolic rate as predictors of weight gain: the Baltimore Longitudinal Study on Aging.

The authors followed 775 men (aged 18-98 years) participating in the Baltimore Longitudinal Study in Aging for an average of ten years. Resting metabolic rate and fasting respiratory exchange ratio (RER) were measured by indirect calorimetry on their first visit and related to subsequent weight change. Deviations from the predicted value of resting metabolic rates (predicted from their estimated fat-free mass) were calculated. Average weight change was 0.07 kg (s.d. 6.4 kg); 122 men (15.3%) gained more than 5 kg and 40 (5.2%) more than 10 kg during the follow-up. After adjustment for initial age, body mass index, fat-free mass, and duration of follow-up, RER, but not RMR or deviations from predicted RMR, was positively related to weight change (P less than 0.001). Major weight gain (from at least 5 kg to at least 15 kg) was related to initial RER in non-obese men only (initial body mass index less than 25 kg/m2). From Cox proportional hazard regression analyses the adjusted relative risk of gaining 5 kg or more in initially non-obese men with a fasting RER of 0.85 or more was calculated to be 2.42 (95% confidence interval: 1.10-5.32) compared to men with a fasting RER less than 0.76. It was concluded that a relatively high fasting RER is a weak but significant predictor of substantial weight gain in non-obese white men.     

Resting energy expenditure and fuel metabolism following laparoscopic adjustable gastric banding in severely obese women: relationships with excess weight lost

BACKGROUND: Although adjustable gastric banding is increasingly proposed for massively obese patients, little is known about the modifications of resting metabolic rate and substrate oxidation or about metabolic determinants of weight loss following this type of bariatric surgery. OBJECTIVES: To evaluate the relationships between excess weight loss, resting metabolic rate (RMR) and substrate oxidation, and to identify metabolic predictive factors of weight loss after adjustable gastric banding. SUBJECTS: Seventy-three obese nondiabetic women aged 39.1+/-10.4 years (18.4-64.8). DESIGN: Resting metabolic rate and substrate oxidation (indirect calorimetry), body composition (bio-impedance), lipid profile and insulin sensitivity indexes were assessed before and after (13.3+/-6.0 months, range 6.0-31.1) adjustable gastric banding. Patients were classified according to postsurgery time: group A (6-12 months, n=39); group B (12-18 months, n=21); group C (>18 months, n=13). Metabolic parameters associated with the percentage of excess weight lost (EWL) 1 year after surgery were analyzed in univariate and multivariate regressions. RESULTS: Mean weight loss was 26.2+/-11.4 kg. Mean fat mass loss was 17.3+/-8.1 kg. All biological parameters associated with excess weight improved after surgery. Excess weight lost at 1 year was 45.9+/-17.1% in group A, 47.4+/-17.1% in group B and 51.4+/-18.5% in group C (P=NS). Resting metabolic rate/fat-free mass (FFM) slightly decreased (28.9+/-3.26 vs 30.3+/-2.8, P<0.00001) and RMR/body weight slightly increased (18.5+/-2.8 vs 17.3+/-1.9, P<0.00001) after surgery. Respiratory quotient (0.81+/-0.06 vs 0.82+/-0.05) and FFM-adjusted lipid oxidation (1.10+/-0.41 vs 1.05+/-0.33 mg/min/kg FFM) were not significantly modified after surgery. In multiple linear regression analysis, difference in RMR/body weight, difference in energy sparing, baseline BMI and postsurgery time, were significantly and independently correlated with EWL (total R2=72.5%). CONCLUSIONS: Adjustable gastric banding promotes gradual but sustained weight loss and is associated with long-term conservation of lipid oxidation and energy expenditure. The individual variability in energy sparing mechanisms predicts weight loss during the first year after surgery.     

The effect of orlistat-induced weight loss on interleukin-6 and C-reactive protein levels in obese subjects

OBJECTIVE: Inflammation plays a major role in the pathogenesis of atherosclerosis. Obesity is an independent risk factor for cardiovascular disease, which may be mediated by increased secretion of proinflammatory cytokines by adipose tissue. The aim of this study is to investigate changes in the inflammatory markers interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) during weight reduction with orlistat treatment in obese patients. METHODS AND RESULTS: Thirty-six obese (BMI: 36.1 +/- 3.4 kg/m2) and II non-obese (BMI: 22.9 +/- 1.7 kg/m2) subjects were studied. IL-6 and hs-CRP levels were evaluated at baseline. In obese subjects after treatment of orlistat 120 mg three times daily for 6 months, IL-6 and hs-CRP levels were repeated. Levels of circulating IL-6 (p < 0.05) and hs-CRP (p < 0.01) were significantly higher in the obese group than in the non-obese group. Plasma IL-6 (r = 0.29 and p < 0.05) and CRP (r = 0.35 and p < 0.05) concentrations correlated positively with the level of obesity assessed by BMI at baseline. After 6 months of orlistat treatment in obese subjects, the mean weight of the patients decreased by 6.8 kg, the BMI by 3.2 kg/m2. Compared with baseline, weight loss was associated with significant reductions of IL-6 (p < 0.001) and hs-CRP (p < 0.001) levels. CONCLUSION: In summary plasma IL-6 and hs-CRP levels were increased in obese patients. Orlistat-induced weight reduction was associated with decreasing levels of both IL-6 and hs-CRP in obese subjects. Because inflammatory mediators may be directly involved in atherogenesis, this would suggest that interventions to reduce IL-6 and CRP levels could be cardioprotective.     

Sleeping metabolic rate in relation to body mass index and body composition

OBJECTIVES: To determine whether patterns of sleeping metabolic rate (SMR) are altered in obesity. Specifically to determine the relationship between changes in SMR and body weight, body mass index (BMI, kg/m(2)), and fat-free mass (FFM); and to compare resting metabolic rate (RMR) with SMR during different periods of sleep. SUBJECTS: Eighteen healthy, pre-menopausal, obese (BMI >30, n=9) and non-obese (BMI <30, n=9), female subjects (six Caucasians and 12 African-Americans), with an average age of 36 y (range 22-45). MEASUREMENTS: Total energy expenditure (TEE or 24 h EE), metabolic rate (MR), SMR (minimum, average and maximum) and resting metabolic rate (RMR) or resting energy expenditure (REE) measured by human respiratory chamber, and external mechanical work measured by a force platform within the respiratory chamber. Physical activity index (PAL) was derived as TEE/REE. Body composition was determined by dual-energy X-ray absorptiometry (DXA). RESULTS: SMR decreased continuously during sleep and reached its lowest point just before the subject was awakened in the morning by the research staff. Although averages for RMR and SMR were similar, RMR was lower than SMR at the beginning of the sleeping period and higher than SMR in the morning hours. The rate of decrease in SMR was faster with increasing body weight (-0.829, P<0.0001), BMI (correlation factor -0.896, P<0.0001) and FFM (-0.798, P=0.001). The relationship between the slope of SMR decrease and BMI (y=-5 x 10(-6)x(2)+0.0002x-0.0028) is highly significant, with a P-value of <0.0001 and r(2) value of 0.9622. CONCLUSIONS: The rate of decline in metabolic rate during sleep is directly related to body weight, BMI and FFM. Average SMR tends to be lower than RMR in obese subjects and higher than RMR in non-obese subjects.