Do obese patients after weight loss become metabolically normal?

Association Between Weight Change and Increased Likelihood of Abdominal Aortic Calcification Among Men

OBJECTIVE

We aimed to explore the effect of weight change on abdominal aortic calcification (AAC) among men.

METHODS

Data were obtained from the 2013 to 2014 National Health and Nutrition Examination Survey (NHANES). Self-reported cardiovascular disease patients were excluded. Lateral spine images were used to quantify AAC score and severe AAC was defined as a AAC score greater than 6. Weight change over a 10-year period was defined as long-term weight change, and weight change over a 1-year period was defined as short-term weight change. The relationship between long-term and short-term weight change with AAC grade was estimated by using multivariable regression analysis and subgroup analysis.

RESULTS

After adjusting for covariates, weight gain, especially severe weight gain (> 10 kg), was associated with increased likelihood of AAC and severe AAC both in the short term (1 year) and long term (10 years) among men when compared to stable weight change, while long-term weight loss could also lead to an increased likelihood of AAC and severe AAC.

CONCLUSION

Stable body weight might be a predictor of a lower risk of AAC and severe AAC among men in the long term and short term.

Improved metabolism and body composition beyond normal levels following gastric bypass surgery: a longitudinal study

BACKGROUND

The cardiometabolic risk profile improves following bariatric surgery. However, the degree of improvement in relation to weight-stable control subjects is unknown.

OBJECTIVES

To study the differences in cardiometabolic risk profile between formerly obese patients following Roux-en-Y gastric bypass (RYGB) surgery and control subjects.

METHODS

Subjects undergoing RYGB and reaching a BMI <30 kg m^-2 2 years postsurgery were matched with control subjects regarding age, sex and BMI. The following examinations were performed: insulin sensitivity measured by hyperinsulinaemic-euglycaemic clamp, insulin clearance, homeostatic model assessment of insulin resistance (HOMA-IR), lipid profile, inflammatory marker levels, dual-energy X-ray absorptiometry and subcutaneous adipose tissue cellularity (fat cell size and number).

RESULTS

Sixty-nine subjects undergoing RYGB were matched to a control subject. Insulin sensitivity measured by hyperinsulinaemic-euglycaemic clamp, blood pressure, inflammatory status and glucose, triglyceride and HDL cholesterol levels were comparable to values of control subjects. However, HOMA-IR (1.0 ± 0.5 vs. 1.3 ± 0.7, P = 0.005), insulin clearance (0.38 ± 0.08 vs. 0.34 ± 0.08 μL m^-2  min^-1 , P < 0.0001) and circulating levels of insulin (31 ± 15 vs. 37 ± 17 pmol L^-1 , P = 0.008), total cholesterol (4.1 ± 0.7 vs. 4.8 ± 0.9 mmol L^-1 , P < 0.0001) and LDL cholesterol (2.1 ± 0.6 vs. 2.9 ± 0.8 mmol L^-1 , P < 0.0001) were improved beyond the levels in matched control subjects. Furthermore, formerly obese subjects had higher lean and lower fat mass as well as a more benign type of adipose cellularity (hyperplasia with many small fat cells) compared to control subjects.

CONCLUSIONS

Subjects who underwent RYGB and reached a postobese state demonstrated a beneficial body composition, slightly increased insulin sensitivity as indirectly measured by HOMA-IR and higher insulin clearance, lower atherogenic lipid/lipoprotein levels and benign adipocyte morphology compared with control subjects who had never been obese. In line with previous results, our findings may in part explain why RYGB confers long-term protection against metabolic complications.

Long-term Protective Changes in Adipose Tissue After Gastric Bypass

OBJECTIVE

Although long-term weight regain may occur after bariatric surgery, many patients are protected against relapse or development of type 2 diabetes. The study objective was to investigate whether this involves beneficial changes in adipose function.

RESEARCH DESIGN AND METHODS

Forty-nine obese women were investigated before and 2 and 5 years after Roux-en-Y gastric bypass (RYGB). At the 5-year follow-up, 30 subjects were pairwise matched for BMI and age to 30 control women. Clinical parameters and fine-needle biopsies from subcutaneous abdominal adipose tissue were obtained; fat cell size and number, lipolysis, adiponectin, and proinflammatory protein secretion were determined.

RESULTS

After 2 years, BMI decreased from 43 to 29 kg/m², which was accompanied by improvements in insulin sensitivity (HOMA of insulin resistance [HOMA-IR]), increased circulating and adipose secreted adiponectin, and decreased adipose lipolysis and fat cell size but no change in adipocyte number. Between 2 and 5 years after surgery, BMI had increased to 31 kg/m². This was associated with slightly increased HOMA-IR and unaltered circulating or adipose secreted adiponectin but higher secretion of tumor necrosis factor-α and increased lipolysis and number of fat cells but no change in adipocyte size. All these parameters, except lipolysis, were significantly more favorable compared with those in matched control subjects. Furthermore, the relationship between HOMA-IR and circulating adiponectin was less steep than in control subjects.

CONCLUSIONS

RYGB improves long-term insulin sensitivity and adipose phenotypes beyond the control state despite weight regain. Postoperative beneficial alterations in adipose function may be involved in the diabetes-protective effect of bariatric surgery.

Incidence and potential risk factors of obesity among Tehranian adults

AIM

Evaluating the incidence of obesity and its risk factors among Tehranian adults.

MATERIAL & METHODS

In this population-based cohort, non-obese participants, aged ≥20years, were followed for development of obesity (Body Mass Index (BMI) ≥30). Incidence density and cumulative incidence rates of obesity were calculated for each sex. Cox proportional hazard regression was used to determine the association of potential obesity risk factors including: age, BMI, metabolic syndrome, waist circumference (WC), smoking, marital status, education, and physical activity.

RESULT

A total of 7257 participants (3536 men) were followed for a median of 8years. At baseline, mean age, BMI and WC were 41.3±14.6years, 25.1±2.9kg/m(2) (24.9±3kg/m(2) men and 25.2±3kg/m(2) women), and 84.8±9.8cm (87.06±9.2cm men and 82.6±9.9cm women) respectively. During the follow-up, 1345 participants (876 women) developed obesity contributing to cumulative incidences of 31.3% (CI: 29.9%-32.7%), 38.1% (CI: 36.2%-40.1%), and 23.4% (CI: 21.6%-25.3%) for the whole population, women, and men, respectively. Corresponding incidence density rates per 1000 person-year were 25.9 (CI: 24.5-27.3), 33.67 (CI: 31.5-36.0), and 18.0 (CI: 16.5-19.7), respectively. Highest incidence rates were observed during their 40s and 20s for women and men, respectively. Participants with metabolic syndrome, lower educational level, higher BMI and WC, were at higher risk of obesity development in both sexes.

CONCLUSION

High incidence of obesity was observed among Tehranian adults with higher incidence of obesity in women. Different modifiable variables may act as risk factors for obesity development which should be targeted to control the epidemic of obesity.

Short-term obesity results in detrimental metabolic and cardiovascular changes that may not be reversed with weight loss in an obese dog model

The time course of metabolic and cardiovascular changes with weight gain and subsequent weight loss has not been elucidated. The goal of the present study was to determine how weight gain, weight loss and altered body fat distribution affected metabolic and cardiovascular changes in an obese dog model. Testing was performed when the dogs were lean (scores 4-5 on a nine-point scale), after ad libitum feeding for 12 and 32 weeks to promote obesity (>5 score), and after weight loss. Measurements included serum glucose and insulin, plasma leptin, adiponectin and C-reactive protein, echocardiography, flow-mediated dilation and blood pressure. Body fat distribution was assessed by computed tomography. Fasting serum glucose concentrations increased significantly with obesity (P< 0·05). Heart rate increased by 22 (SE 5) bpm after 12 weeks of obesity (P= 0·003). Systolic left ventricular free wall thickness increased after 12 weeks of obesity (P= 0·002), but decreased after weight loss compared with that observed in the lean phase (P= 0·03). Ventricular free wall thickness was more strongly correlated with visceral fat (r 0·6, P= 0·001) than with total body fat (r 0·4, P= 0·03) and was not significantly correlated with subcutaneous body fat (r 0·3, P= 0·1). The present study provides evidence that metabolic and cardiovascular alterations occur within only 12 weeks of obesity in an obese dog model and are strongly predicted by visceral fat. These results emphasise the importance of obesity prevention, as weight loss did not result in the return of all metabolic indicators to their normal levels. Moreover, systolic cardiac muscle thickness was reduced after weight loss compared with the pre-obesity levels, suggesting possible acute adverse cardiovascular effects.

Effects of equine metabolic syndrome on inflammatory responses of horses to intravenous lipopolysaccharide infusion

OBJECTIVE

To test the hypothesis that inflammatory responses to endotoxemia differ between healthy horses and horses with equine metabolic syndrome (EMS). Animals-6 healthy horses and 6 horses with EMS.

PROCEDURES

Each horse randomly received an IV infusion of lipopolysaccharide (20 ng/kg [in 60 mL of sterile saline {0.9% NaCl} solution]) or saline solution, followed by the other treatment after a 7-day washout period. Baseline data were obtained 30 minutes before each infusion. After infusion, a physical examination was performed hourly for 9 hours and at 15 and 21 hours; a whole blood sample was collected at 30, 60, 90, 120, 180, and 240 minutes for assessment of inflammatory cytokine gene expression. Liver biopsy was performed between 240 and 360 minutes after infusion. Results-Following lipopolysaccharide infusion in healthy horses and horses with EMS, mean rectal temperature, heart rate, and respiratory rate increased, compared with baseline findings, as did whole blood gene expression of interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor-α. The magnitude of blood cytokine responses did not differ between groups, but increased expression of IL-6, IL-8, IL-10, and tumor necrosis factor-α persisted for longer periods in EMS-affected horses. Lipopolysaccharide infusion increased liver tissue gene expressions of IL-6 in healthy horses and IL-8 in both healthy and EMS-affected horses, but these gene expressions did not differ between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Results supported the hypothesis that EMS affects horses' inflammatory responses to endotoxin by prolonging cytokine expression in circulating leukocytes. These findings are relevant to the association between obesity and laminitis in horses with EMS.