Reductions in arterial stiffness with weight loss in overweight and obese young adults: Potential mechanisms

ObjectiveArterial stiffness decreases with weight loss in overweight/obese young adults. We aimed to determine the mechanisms by which this occurs.MethodsWe evaluated carotid-femoral pulse wave velocity (cfPWV) and brachial-ankle pulse wave velocity (baPWV) in 344 young adults (23% male, BMI 25–40 kg/m²) at baseline, 6, and 12 months in a behavioral weight loss intervention. Linear mixed models were used to evaluate associations between weight loss and arterial stiffness and to examine whether improvements in obesity-related factors explained these associations.ResultsAt 6 months (7% mean weight loss), there was a significant median decrease of 47.5 cm/s in cfPWV (p < 0.0001) and a mean decrease of 11.7 cm/s in baPWV (p = 0.049). At 12 months (6% mean weight loss), only cfPWV remained reduced. In models adjusting for changes in mean arterial pressure and obesity-related factors, changes in BMI (p = 0.01) and common carotid artery diameter (p = 0.003) were positively associated with change in cfPWV. Reductions in heart rate (p < 0.0001) and C-reactive protein (p = 0.02) were associated with reduced baPWV and accounted for the association between weight loss and reduced baPWV.ConclusionsWeight loss is associated with reduced cfPWV independently of changes in established hemodynamic and cardiometabolic risk factors, but its association with reduced baPWV is explained by concurrent reductions in heart rate and inflammation.     

Medical strategies for weight loss in the overweight and obese patient

In recent years, obesity has become a major public health problem in Western countries. The World Health Organization has defined obesity as a global epidemic of the third millennium. Treatment options for weight management include dietary intervention, physical activity, behavior modification, pharmacotherapy and surgery. However, the complexity of this chronic condition necessitates a coordinated multidisciplinary team-approach to the care of obese patients who fail weight control. The long-term duration of the treatment and the necessity of monitoring compliance and effectiveness should be considered. The objective of this article was to review the major controlled randomized clinical trials dealing with the different medical strategies for weight loss and its maintenance in overweight and obese patients.     

Sleep duration and weight loss among overweight/obese women enrolled in a behavioral weight loss program

Objective:

The purpose of this study was to examine whether baseline sleep duration predicts weight loss outcomes in a randomized controlled trial examining a behavioral weight loss (BWL) intervention among overweight and obese (OW/OB) women with urinary incontinence; and whether participation in the BWL intervention is associated with changes in sleep duration.

Design:

Longitudinal, clinical intervention study of a 6-month BWL program.

Subjects:

Three hundred sixteen OW/OB women, with urinary incontinence (age: 30–81 years, body mass index (BMI; 25–50 kg m⁻²) enrolled from July 2004–April 2006.

Measurements:

Measured height and weight, self-report measures of demographics, sleep and physical activity.

Results:

Neither self-reported total sleep time (TST) nor time in bed (TIB) at baseline significantly predicted weight loss outcomes among OW/OB women in a BWL treatment. BWL treatment was successful regardless of how much subjects reported sleeping at baseline, with an average weight loss of 8.19 kg for OW/OB women receiving BWL treatment, versus a weight loss of 1.44 kg in the control condition. Similarly, changes in weight, BMI and incontinence episodes did not significantly predict changes in sleep duration or TIB across the treatment period.

Conclusion:

Although epidemiological and cross-sectional studies support a relationship between short sleep and increased BMI, the present study found no significant relationship between TST or TIB and weight loss for OW/OB women participating in a BWL treatment.     

Higher sleep fragmentation predicts a lower magnitude of weight loss in overweight and obese women participating in a weight-loss intervention

Background:

Sleep has been identified as having an influence on the success of weight-loss interventions; however, knowledge of the mechanisms and the extent to which sleep disturbances affect the magnitude of weight reduction is inconclusive.

Objective:

To determine if sleep duration and quality can predict the magnitude of weight reduction in a weight-loss intervention program for overweight and obese women.

Methods:

Ninety overweight and obese women aged 25–65 years completed the 7-month weight-loss phase of our weight-loss intervention. Sleep duration and quality were evaluated before the intervention by the Pittsburg Sleep Quality Index (PSQI), a self-report questionnaire, and by actigraphy. Serum levels of ghrelin, leptin, cortisol and insulin also were measured at baseline. Insulin resistance was measured by the homeostasis model assessment of insulin resistance (HOMA-IR).

Results:

The mean reduction rate of body mass index (BMI) after the intervention was 13.6%. Multiple linear regression revealed that the number of wake episodes (WEs) per night had a significant relationship with the reduction of BMI even after adjusting for other clinical variables (β=−0.341, P=0.001). The participants with five or more WEs per night (high-WE group) had a significantly lower reduction in BMI compared with those with fewer than five (normal-WE group), after adjusting for confounding variables. In contrast, the PSQI-assessed parameters, reflecting the subjective assessments of sleep quality and duration, failed to detect an association with the reduction in BMI. Baseline HOMA-IR was significantly higher in the high-WE group than in the normal-WE group after adjusting for confounding variables.

Conclusions:

Higher sleep fragmentation, as manifested by the increased number of WEs, predicts a lower magnitude of weight reduction in persons participating in weight-loss programs.     

Consumption of cod and weight loss in young overweight and obese adults on an energy reduced diet for 8-weeks

Background and aimsIn a cross-European study it was recently shown that consumption of cod increases weight loss in men and also has other positive health effects. The aim of this study was to investigate whether cod consumption increases weight loss and improves cardiovascular risk factors in a dose dependent manner during an 8-week energy restriction diet in young overweight and obese healthy adults.Methods and resultsIn this dietary intervention 126 subjects (20–40 years, BMI 27.5–32.5 kg/m²) comprised the group given energy-restricted diets (−30%); they were prescribed an identical macronutrient composition but different amounts of cod: the control group were given no seafood; group 1 were given 150 g cod 3 times a week; and group 2 were given 150 g cod 5 times a week. Anthropometric measurements and cardiovascular risk factors were assessed at baseline and endpoint. Body weight decreased after 8-weeks (5.0 ± 2.9 kg, P < 0.001), also waist circumference (5.0 ± 3.2 cm, P < 0.001), BMI (1.65 ± 0.95 kg, P < 0.001), systolic (3.4 ± 8.9 mmHg, P = 0.001) and diastolic blood pressure (2.4 ± 6.9 mmHg, P < 0.001), triglycerides (1.26 ± 0.567 mmol/L, P = 0.030) and insulin (1.21 ± 5.31 mU/L, P = 0.025). The prevalence of the metabolic syndrome dropped from 29 to 21%. According to linear models weight loss was 1.7 kg greater among subjects consuming 150 g 5×/week compared to the control group (P < 0.015). The trend analysis supported a dose-response relationship between cod consumption and weight loss (P < 0.001), but changes of other measured cardiovascular risk factors were similar between the groups.ConclusionA dose-response relationship between cod consumption and weight loss during an 8-week energy restriction diet is found and 5 × 150 g cod/week results in 1.7 kg greater weight loss in young overweight or obese adults than a isocaloric diet without seafood.     

Relationship between costs of lifestyle interventions and weight loss in overweight adults

Lifestyle interventions in a healthcare setting are effective for weight loss, but it is unclear whether more expensive interventions result in more weight loss. Our objective was to explore the relationship between intervention costs and effectiveness in a systematic review of randomized trials.
Intervention studies were selected from 14 reviews and from a systematic MEDLINE-search. Studies had to contain a dietary and a physical activity component and report data on measured weight loss in healthy Caucasian overweight adults. Intervention costs were calculated in a standardized way. The association between costs and percentage weight loss after 1 year was assessed using regression analysis.
Nineteen original studies describing 31 interventions were selected. The relationship between weight loss and intervention costs was best described by an asymptotic regression model, which explained 47% of the variance in weight loss. A clinically relevant weight loss of 5% was already observed in interventions of approximately €110. Results were similar in an intention-to-treat analysis.
In conclusion, lifestyle interventions in health care for overweight adults are relatively cheap and higher intervention costs are associated with more weight loss, although the effect of costs on weight loss levels off with growing costs.     

Eating control and physical activity as determinants of short-term weight maintenance after a very-low-calorie diet among obese women

OBJECTIVE: To test the hypothesis that eating control and physical activity help maintain weight and waist circumference after a very-low-calorie diet. DESIGN: A 12 week weight reduction (WR) phase, followed by a 40 week weight maintenance (WM) phase. For the latter, the subjects were randomised into a no-exercise group and one of two groups with a walking program. SUBJECTS: Eighty-five obese (body mass index 29-46, mean 34), clinically healthy, premenopausal women. MEASUREMENTS: Body weight, waist circumference, body composition, the measuring restrained eating, disinhibition and hunger, measured by Three Factor Eating Questionnaire (TFEQ), binge eating measured by the Bulimic Investigatory Test of Edinburgh (BITE), and number of daily steps measured by a pedometer. RESULTS: The change (delta) in weight during WM was predicted by the following regression: deltaweight (kg)=5.23+0.45 deltaweight during WR+0.66 disinhibition during WM0.00039 daily steps during WM, r2=0.46, SEE 3.3 kg. The change in waist circumference during WM was predicted as deltawaist (cm)=0.76+0.75 deltaweight during WM0.00021 daily steps during WM, r2=0.67, SEE 2.6 cm. Exercise group assignment did not affect the changes in weight, waist circumference, or indicators of eating control during the maintenance program. CONCLUSIONS: Control of overeating, as indicated by a lower disinhibition factor of the TFEQ, and daily physical activity, as indicated by a higher number of daily steps, were positive and independent predictors of weight maintenance after a very-low-calorie diet. The number of daily steps showed an independent association with change in waist circumference during weight maintenance, even after adjustment for weight change.     

Incremental weight loss improves cardiometabolic risk in extremely obese adults

Objective

Excessively obese adults often acquire many metabolic disorders that put them at high risk for developing type 2 diabetes mellitus and cardiovascular disease. We investigated the hypothesis that cardiometabolic risk in a primary care cohort of 208 excessively obese adults (body mass index 40-60 kg/m², 48 with type 2 diabetes mellitus) would deteriorate with additional weight gain and improve incrementally beginning with 5% weight reduction.

Methods

Further analysis of the Louisiana Obese Subjects Study of excessively obese patients enrolled and followed during 2005-2008 is reported.

Results

Weight loss correlated significantly with improvements in fasting plasma glucose, triglycerides, high- and low-density lipoprotein cholesterol, uric acid, alanine aminotransferase, lactate dehydrogenase, and high-sensitivity C-reactive protein. Most parameters deteriorated with weight gain and progressively improved with 5% or more weight loss. Except for low-density lipoprotein cholesterol, all risk factors significantly improved with ≥ 20% loss of body weight. Among patients who had not been diagnosed with type 2 diabetes mellitus and had normoglycemia at baseline, median fasting plasma glucose increased significantly (13%) with stable or gained weight at 1 year, but did not change significantly with reduced weight. Although glucose levels did not change significantly in patients with type 2 diabetes mellitus who gained weight, a decline beginning after 5% weight reduction culminated in 25% glucose reduction with ≥ 20% weight loss. Resting blood pressure declined independently of weight change.

Conclusion

Very obese adults can improve their cardiometabolic risk under primary care weight management. Incremental success may help motivate further therapeutic weight reduction.     

Effectiveness of web‐based interventions in achieving weight loss and weight loss maintenance in overweight and obese adults: a systematic review with meta‐analysis

The objectives of this systematic review are to evaluate the effectiveness of web‐based interventions on weight loss and maintenance and identify which components of web‐based interventions are associated with greater weight change and low attrition rates. A literature search from 1995 to April 2008 was conducted. Studies were eligible for inclusion if: participants were aged ≥18 years with a body mass index ≥25, at least one study arm involved a web‐based intervention with the primary aim of weight loss or maintenance, and reported weight‐related outcomes. Eighteen studies met the inclusion criteria. Thirteen studies aimed to achieve weight loss, and five focused on weight maintenance. Heterogeneity was evident among the studies with seven research questions examined across interventions of varying intensity. Seven studies were assessed for effectiveness based on percentage weight change, with four studies deemed effective. Although the four meta‐analyses suggest meaningful weight change, it is not possible to determine the effectiveness of web‐based interventions in achieving weight loss or maintenance due to heterogeneity of designs and thus the small number of comparable studies. Higher usage of website features may be associated with positive weight change, but we do not know what features improve this effect or reduce attrition.     

Effect of weight loss and exercise on frailty in obese older adults

BACKGROUND: Obesity exacerbates the age-related decline in physical function and causes frailty in older persons. However, appropriate treatment for obese older persons is unknown. We evaluated the effects of weight loss and exercise therapy on physical function and body composition in obese older persons. METHODS: We screened 40 obese older volunteers and eventually randomized 27 frail obese older volunteers to treatment or control groups. Treatment consisted of 6 months of weekly behavioral therapy for weight loss in conjunction with exercise training 3 times per week. Physical function was evaluated with measurements of frailty (Physical Performance Test, peak oxygen consumption, and Functional Status Questionnaire); strength, gait, and balance tests; body composition with dual-energy x-ray absorptiometry; and quality of life using the Medical Outcomes Survey 36-Item Short-Form Health Survey. Results are reported as mean +/- SD. RESULTS: Two subjects in the treatment group did not comply with the intervention, and 1 subject in the control group withdrew. Analyses included all 27 subjects originally randomized to the treatment and control groups. The treatment group lost 8.4% +/- 5.6% of body weight, whereas weight did not change in the control group (+0.5% +/- 2.8%; P<.001). Compared with the control group, fat mass decreased (-6.6 +/- 3.4 vs +1.7 +/- 4.1 kg; P<.001), without a change in fat-free mass (-1.2 +/- 2.1 vs -1.0 +/- 3.5 kg; P = .75) in the treatment group. The Physical Performance Test score (2.6 +/- 2.5 vs 0.1 +/- 1.0; P = .001), peak oxygen consumption (1.7 +/- 1.6 vs 0.3 +/- 1.1 mL/min per kilogram; P = .02), and Functional Status Questionnaire score (2.9 +/- 3.7 vs -0.2 +/- 3.9; P = .02) improved in treated subjects compared with control subjects. Treatment also improved strength, walking speed, obstacle course, 1-leg limb stance time, and health survey physical subscale scores (all P<.05). CONCLUSION: These findings suggest that weight loss and exercise can ameliorate frailty in obese older adults.Trial Registration clinicaltrials.gov Identifier: NCT00146133.     

Effects of weight loss on insulin sensitivity and arterial stiffness in overweight adults

Obesity is characterized by metabolic and vascular abnormalities. We examined the effects of weight loss on insulin sensitivity and arterial stiffness in overweight adults. Twelve (9 females; 3 males) overweight (body mass index, 30.3 +/- 3.7) adults (54.9 +/- 3.9 years) without diabetes or vascular disease were counseled by a registered dietician to lose weight over 6 months. Vascular structure, function, and wall mechanical properties were measured via ultrasound. Intravenous glucose tolerance test, 24-hour blood pressure, body composition (dual-energy x-ray absorptiometry), and lipids were also assessed. There were significant reductions in body mass (86.3 +/- 14.2 vs 79.5 +/- 13.8 kg, P < .0001) and percentage of fat (44.3% +/- 7.0% vs 41.0% +/- 8.5%, P < .01) after weight loss. There were significant improvements in total cholesterol (6.0 +/- 0.9 vs 5.0 +/- 0.8 mmol/L, P < .0001), low-density lipoprotein cholesterol (3.9 +/- 0.7 vs 3.2 +/- 0.6 mmol/L, P < .0001), triglycerides (3.4 +/- 2.3 vs 2.4 +/- 0.9 mmol/L, P < .05), and insulin sensitivity (3.3 +/- 1.7 vs 5.4 +/- 1.6 microU x 10(-4) min(-1) mL(-1), P < .0001) after weight loss. Brachial artery compliance (P < .05) and distensibility (P < .05) curves over the physiologic pressure range improved, whereas endothelial function and intima-media thickness remained unchanged. In overweight adults, 6 months of weight loss resulted in improvements in body composition, insulin sensitivity, lipid profile, and brachial artery compliance and distensibility.     

Long-term weight loss effects on all cause mortality in overweight/obese populations

This systematic review assesses the long-term effectiveness of weight loss on all cause mortality in overweight/obese people. Medline, Embase and Cinahl were searched (1966-2005). Cohort studies and trials on participants with body mass index > or =25 kg m(-2), with weight change and mortality with > or =2-year follow-up, were included finally identifying 11 papers based on eight studies. There may be gender differences in the benefits for all cause mortality. The impact of weight loss in men on mortality was not clear with some studies indicating weight loss to be detrimental, while a recent cohort study showed benefits, if it were a personal decision. Other studies with no gender separation had similarly mixed results. However, one study indicated that overweight/obese women with obesity-related illness, who lost weight intentionally within 1 year, had significantly reduced mortality rates of 19-25%. In contrast, studies of overweight/obese diabetics irrespective of gender showed significant benefit of intentional weight loss on mortality in a meta-analysis, hazard ratios = 0.75 (0.67-0.83). There is some evidence that intentional weight loss has long-term benefits on all cause mortality for women and more so for diabetics. Long-term effects especially for men are not clear and need further investigation.     

Weight loss reduces knee-joint loads in overweight and obese older adults with knee osteoarthritis

OBJECTIVE: To determine the relationship between change in body mass and knee-joint moments and forces during walking in overweight and obese older adults with knee osteoarthritis (OA) following an 18-month clinical trial of diet and exercise. METHODS: Data were obtained from 142 sedentary, overweight, and obese older adults with self-reported disability and radiographic evidence of knee OA who underwent 3-dimensional gait analysis. Gait kinetic outcome variables included peak knee-joint forces and peak internal knee-joint moments. Mixed regression models were created to predict followup kinetic values, using followup body mass as the primary explanatory variable. Baseline body mass was used as a covariate, and thus followup body mass was a surrogate measure for change in body mass (i.e., weight loss). RESULTS: There was a significant direct association between followup body mass and peak followup values of compressive force (P = 0.001), resultant force (P = 0.002), abduction moment (P = 0.03), and medial rotation moment (P = 0.02). A weight reduction of 9.8 N (1 kg) was associated with reductions of 40.6 N and 38.7 N in compressive and resultant forces, respectively. Thus, each weight-loss unit was associated with an approximately 4-unit reduction in knee-joint forces. In addition, a reduction in body weight of 9.8 N (1 kg) was associated with a 1.4% reduction (0.496 Nm) in knee abduction moment. CONCLUSION: Our results indicate that each pound of weight lost will result in a 4-fold reduction in the load exerted on the knee per step during daily activities. Accumulated over thousands of steps per day, a reduction of this magnitude would appear to be clinically meaningful.     

Effects of moderate consumption of white wine on weight loss in overweight and obese subjects

BACKGROUND: Patients on dietary, weight-reducing treatment commonly are advised against alcohol consumption. In light of the widespread use of alcoholic beverages and the well-established benefits of light to moderate alcohol consumption in risk reduction, a revision of dietary treatment recommendations may be warranted. OBJECTIVE: To investigate whether daily consumption of moderate amounts of alcohol influences the effectiveness of an energy-restricted diet in overweight and obese subjects. DESIGN: A prospective randomized clinical trial was conducted, with a 3-months intervention period and two isocaloric dietary regimens containing 6.3 MJ (1500 kcal) each, one with 10% of energy from white wine and one with 10% of energy from grape juice. The trial was performed in obese subjects being recruited from the Obesity Outpatient Clinic at the University Hospital, Ulm, who all habitually consumed moderate amounts of alcohol. Out of 87 patients, 49 were eligible to participate and 40 completed the study (age 48.1+/-11.4 y, BMI 34.2+/-6.4 kg/m(2)). Efficacy parameters were body weight and biomarkers of good health. RESULTS: All subjects achieved significant body weight reduction. Weight loss in the grape juice group and white wine group was 3.75+/-0.46 and 4.73+/-0.53 kg, respectively. Percent body fat, waist circumference, blood pressure, blood glucose, insulin, triglycerides, and cholesterol were reduced. The antioxidant status was unchanged, as were liver enzyme activities and other safety parameters. There were no significant differences between the groups. CONCLUSIONS: An energy-restricted diet is effective in overweight and obese subjects used to drinking moderate amounts of alcohol. A diet with 10% of energy derived from white wine is as effective as an isocaloric diet with 10% of energy derived from grape juice.