Results of Expert Meetings: Obesity and Cardiovascular Disease. Obesity assessment

Prevalence and cardiometabolic risks of normal weight obesity in Chinese population: A nationwide study

BACKGROUND AND AIMS

Several studies have reported increased cardiovascular risks in normal weight obesity (NWO) populations. We aimed to investigate the prevalence of NWO and its relationships with cardiometabolic risks in Chinese patients.

METHODS AND RESULTS

The data were from the 2007-2008 China National Diabetes and Metabolic Disorders Study. The body fat (BF) was measured using the biological impedance method. NWO was defined as a normal BMI (18.5-23.9 kg/m²) but with excess BF% (BF% ≥ 24% for men and ≥33% for women). 23,748 people (9633 males and 14,115 females) were enrolled and the prevalence of NWO was 9.5% for men, 6.06% for women. The prevalence risks of diabetes (odds ratio [OR]1.519, 95% confidence interval [CI] 1.262-1.828), Framingham risk score (FRS) ≥10% (OR 1.973, 95% CI 1.596-2.439), hypertension (OR 1.525, 95% CI 1.333-1.745), and metabolic syndrome Mets (OR 2.175, 95% CI 1.920-2.463) significantly increased in the NWO group compared with the normal group. Subgroup analyses showed that, after ruling out participants with abnormal waist circumference, the male group had similar findings to the overall population; but in the female group, the prevalence risks of FRS ≥10%, hypertension, and Mets increased, although the risk of diabetes did not.

CONCLUSION

NWO is in a relatively high prevalence in Chinese population, and the prevalence of NWO is higher in Chinese men compared to Chinese women. Cardiometabolic risks significantly increase in an NWO population, and such risks persist after excluding the effect of abdominal obesity.

Potential role of liver enzyme levels as predictive markers of glucose metabolism disorders in a Tunisian population

The relationship between liver enzymes and T2D risk is inconclusive. We aimed to evaluate the association between liver markers and risk of carbohydrate metabolism disorders, as well as their discriminatory power, for T2D prediction. This cross-sectional study enrolled 216 participants classified as normoglycemic, prediabetic, newly diagnosed diabetics, and diagnosed diabetics. All participants underwent anthropometric and biochemical measurements. The relationship between hepatic enzymes and glucose metabolism markers was evaluated by analyses of covariance. The associations between liver enzymes and incident carbohydrate metabolism disorders were analyzed through logistic regression and their discriminatory capacity to predict T2D by ROC analysis. High AP, ALT, γGT, and AST levels were independently related to decreased insulin sensitivity. Interestingly, a higher AP level was significantly associated with an increased risk of prediabetes (p = 0.017), newly diagnosed diabetes (p = 0.004), and T2D (p = 0.007). An elevated γGT level was an independent risk factor for T2D (p = 0.032) and undiagnosed T2D (p = 0.010) in prediabetic and normoglycemic subjects, respectively. In ROC analysis, AP was a powerful predictor of incident diabetes and significantly improved T2D prediction. Liver enzymes within the normal range, specifically AP levels, are associated with increased risk of carbohydrate metabolism disorders and significantly improved T2D prediction.

Moderate intensity exercise improves heart rate variability in obese adults with type 2 diabetes

AIM

The aim of this study was to determine the effect of moderate aerobic exercise on heart rate variability (HRV) in obese adults with type 2 diabetes.

METHODS

Forty-one obese adults with type 2 diabetes participated in this study. Anthropometric and metabolic parameters were measured, and resting electrocardiogram (ECG) for the HRV analysis at spontaneous respiration was recorded for 5 min in supine position before and after six months of supervised aerobic training given thrice-a-week.

RESULTS

The mean age, body mass index (BMI), and duration of diabetes of the study population were 44.1 ± 4.5 years, 30.94 ± 1.36 kg/m2, and 16.3 ± 2.7 years, respectively. In time domain variables, standard deviation of all RR intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent RR intervals (RMSSD) and percentage of consecutive RR intervals that differ by more than 50 ms (pNN50) were significantly increased after exercise. In frequency domain variables, high frequency (HF) (ms2) and HF (nu) were significantly increased while low frequency (LF) (ms2) and LF/HF ratio were significantly decreased after exercise. But LF (nu) was unaffected after exercise.

CONCLUSION

This study suggests that thrice-a-week moderate intensity aerobic exercise for six months improves cardiac rhythm regulation as measured by HRV in obese adults with type 2 diabetes.

The relation of anthropometric measurements and insulin resistance in patients with polycystic kidney disease

OBJECTIVE

To examine the frequency of insulin resistance (IR) and its relation with anthropometric measurements in patients with autosomal dominant polycystic kidney disease (ADPKD).

MATERIAL AND METHODS

Nonobese 82 patients with ADPKD and 58 age matched healthy controls were enrolled into the study. None of participants were diabetic or receiving renal replacement therapies (RRT). IR was determined by homeostasis model assessment of insulin resistance (HOMA-IR) formula. Tanita body composition analyzer was used for anthropometric measurements. Creatinine clearance of participant were assessed by the modification of diet in renal diseases (MDRD).

RESULTS

Patients with ADPKD had significantly higher level of urea and creatinine, microalbuminuria, and lower level of MDRD. Body fat distribution and HOMA-IR in both the groups were similar. Systolic and diastolic blood pressure of patients were higher than those of controls.

CONCLUSION

We failed to determine a higher frequency of IR among patients with ADPKD.

Prevalence of obesity and overweight and their related factors among the adults of Mazandaran Province, Iran, in 2010

Background:

Obesity is an unpleasant outcome of changes in the behavior and lifestyle, and it leads to premature inability and loss of job in most cases. This study aimed at determining the prevalence of obesity and overweight conditions and some related factors among the adults in Mazandaran Province, Iran.

Methods:

This cross-sectional study was conducted in 2010. The data collection tool was a standard questionnaire provided by the World Health organization (WHO).The sample of this study was selected from all people in the age range of 15 to 64 who lived in the urban and rural areas of Mazandaran Province. The researchers studied 1000 people (500 males and 500 females). The data were analyzed using mean, standard deviation, chi-squared, linear regression, and Logistic regression in SPSS version 16 software.

Results:

The average and the standard deviation of Body Mass Index (BMI) of the participants was 27.36±6.04 (25.76±4.5 for males and 28.95±6.9 for females), and the average prevalence of overweight was 34% (males: 35.8%, females: 32.2%); the average incidence of obesity was 28.4% (males: 17.8%, females: 39%).It was found that age groups of 35–44 (OR: 3.1, CI: 95%: 1.7–5.8), 45–54 (OR: 3.1, CI: 95%: 1.7–5.8), and 55–64 (OR: 4.02, CI: 95%: 2.1–7.5) and being a housewife (OR: 2.3, 95% CI: 1.03–5.1) were predictive of BMI values equal to or greater than 30.

Conclusion:

The results of this study showed that the prevalence of overweight and obesity was significant among people of Mazandaran Province. Therefore, it is recommended that educational-research centers and health authorities look for appropriate strategies to reduce the prevalence of this problem.

Normal weight obesity: a risk factor for cardiometabolic dysregulation and cardiovascular mortality

AIMS

We hypothesized that subjects with a normal body mass index (BMI), but high body fat (BF) content [normal weight obesity (NWO)], have a higher prevalence of cardiometabolic dysregulation and are at higher risk for cardiovascular (CV) mortality.

METHODS AND RESULTS

We analysed 6171 subjects >20 years of age from the Third National Health and Nutrition Examination Survey (NHANES III) and the NHANES III mortality study, whose BMI was within the normal range (18.5-24.9 kg/m(2)), and who underwent a complete evaluation that included body composition assessment, blood measurements, and assessment of CV risk factors. Survival information was available for >99% of the subjects after a median follow-up of 8.8 years. We divided our sample using sex-specific tertiles of BF%. The highest tertile of BF (>23.1% in men and >33.3% in women) was labelled as NWO. When compared with the low BF group, the prevalence of metabolic syndrome in subjects with NWO was four-fold higher (16.6 vs. 4.8%, P < 0.0001). Subjects with NWO also had higher prevalence of dyslipidaemia, hypertension (men), and CV disease (women). After adjustment, women with NWO showed a significant 2.2-fold increased risk for CV mortality (HR = 2.2; 95% CI, 1.03-4.67) in comparison to the low BF group.

CONCLUSION

Normal weight obesity, defined as the combination of normal BMI and high BF content, is associated with a high prevalence of cardiometabolic dysregulation, metabolic syndrome, and CV risk factors. In women, NWO is independently associated with increased risk for CV mortality.

Relationship between adiponectin and ambulatory blood pressure in obese adolescents

Obesity is associated with elevated blood pressure (BP), insulin resistance, and altered plasma adiponectin levels; the relationship between the biochemical features of obesity and 24-h ambulatory blood pressure (24-h ABP) parameters in adolescents remains unknown. Anthropometric measurements and 24-h ABP monitoring were obtained on 41 obese adolescents with and without type 2 diabetes mellitus (T2DM). Serum adiponectin, high sensitivity C-reactive protein (hs-CRP), lipid profile, insulin, fasting glucose, liver enzymes, Hb A1c (HbA1c), and two random urine samples were obtained for creatinine and microalbumin measurements. The determinants of 24-h systolic (SBP) and diastolic (DBP) BP were examined using multivariate linear regression models with BP parameters as outcome variables. Forty-one obese adolescents were studied. Adiponectin levels were reduced and hs-CRP levels were elevated, and were inversely and significantly correlated (rho = -0.3, p = 0.05). ABP showed blunted nocturnal SBP dipping. Twenty-four hour SBP and DBP indexes were significantly (p < 0.05) and inversely correlated with adiponectin (rho = -0.4 and -0.42), respectively. In multivariate models, lower adiponectin level was independently associated with 24-h SBP and DBP. Adiponectin inversely correlate with ABP parameters in obese adolescents. Larger studies are needed to examine the relationship between adiponectin and mechanisms of BP regulation.

Accuracy of body mass index in diagnosing obesity in the adult general population

BACKGROUND

Body mass index (BMI) is the most widely used measure to diagnose obesity. However, the accuracy of BMI in detecting excess body adiposity in the adult general population is largely unknown.

METHODS

A cross-sectional design of 13 601 subjects (age 20-79.9 years; 49% men) from the Third National Health and Nutrition Examination Survey. Bioelectrical impedance analysis was used to estimate body fat percent (BF%). We assessed the diagnostic performance of BMI using the World Health Organization reference standard for obesity of BF%>25% in men and>35% in women. We tested the correlation between BMI and both BF% and lean mass by sex and age groups adjusted for race.

RESULTS

BMI-defined obesity (> or =30 kg m(-2)) was present in 19.1% of men and 24.7% of women, while BF%-defined obesity was present in 43.9% of men and 52.3% of women. A BMI> or =30 had a high specificity (men=95%, 95% confidence interval (CI), 94-96 and women=99%, 95% CI, 98-100), but a poor sensitivity (men=36%, 95% CI, 35-37 and women=49%, 95% CI, 48-50) to detect BF%-defined obesity. The diagnostic performance of BMI diminished as age increased. In men, BMI had a better correlation with lean mass than with BF%, while in women BMI correlated better with BF% than with lean mass. However, in the intermediate range of BMI (25-29.9 kg m(-2)), BMI failed to discriminate between BF% and lean mass in both sexes.

CONCLUSIONS

The accuracy of BMI in diagnosing obesity is limited, particularly for individuals in the intermediate BMI ranges, in men and in the elderly. A BMI cutoff of> or =30 kg m(-2) has good specificity but misses more than half of people with excess fat. These results may help to explain the unexpected better survival in overweight/mild obese patients.

Prevalence of obesity, central obesity and the associated factors in urban population aged 20-70 years, in the north of Iran: a population-based study and regression approach

Obesity is an undesirable outcome of changing of lifestyle and behaviours. It is also reversible predisposing factor for the development of several debilitating diseases. This study was aimed to determine the prevalence rate of obesity, overweight, central obesity and their associated factors in the north of Iran. We conducted a population-based cross-sectional study with a sample of 1800 women and 1800 men with respective mean ages of 37.5 +/- 13.0 and 38.5 +/- 14.2 years of urban population aged 20-70 years living in the north of Iran. The demographic and lifestyle data, in particular, age, gender, marital status, marriage age, family history of obesity, educational level, occupation, occupational and leisure time physical activity, duration of exercise per week, parity and the number of children were collected with a designed questionnaire. Diagnosis of obesity and central obesity were confirmed by the WHO standard recommended method by determining of body mass index (BMI) and waist circumference (WC). Logistic regression model was used to estimate the adjusted odds ratio (OR) and its 95% confidence interval. Over half of the study subjects were at educational levels of high school or higher; 79.4% of population was married and 35.3% had a family history of parental obesity. The majority of subjects in particular women had none or low levels of physical activity. The overall prevalence rates of obesity and overweight were 18.8% and 34.8% respectively. The overall prevalence rate of central obesity was 28.3%. The rate of obesity in women was higher than men (P < 0.0001). In both genders, particularly in the women, the rate of obesity was raised by increasing age. There was an inverse relation between the risk of obesity and marriage age, the high level of education (OR = 0.19, P < 0.0001), severe occupational activity (OR = 0.44, P < 0.0001), the level of exercise (in subjects with 3-4 h exercise per week, OR = 0.58, P < 0.001) and leisure time activity. Marriage, history of parental obesity and parity > or =5 were associated with increased risk of obesity (OR = 2.2, P < 0.001 and OR = 2.43, P < 0.0001 and OR = 3.73, P < 0.0001 respectively). The results of this study indicate an increased rate of obesity and overweigh in the north population of Iran. With respect to these findings, low level of activity and education, parity, family history of obesity, marriage at earlier age and ageing are responsible for both obesity and central obesity in the north of Iran. Therefore, a community-based multiple strategies are required to combat with increasing rate of obesity and its subsequent complications such as diabetes, coronary artery disease, hypertension and osteoarthritis.

Post-Operative Obesity and Cachexia Are Risk Factors for Morbidity and Mortality After Heart Transplant: Multi-Institutional Study of Post-Operative Weight Change

BACKGROUND

The relationship between post-heart transplant cachexia and obesity with subsequent morbidity and mortality has not yet been reported. Therefore, the purposes of this study were to: (1) describe change in body mass index (BMI) from before transplant through 5 years after transplant; (2) identify risk factors for increased BMI at 1 year post-transplant; and (3) determine whether post-transplant BMI is associated with post-transplant morbidity and mortality.

METHODS

Patients (n = 3,540) were from a non-random sample having received a heart transplant between January 1, 1996 and December 31, 2001 at 33 institutions of the Cardiac Transplant Research Database (CTRD). Patients were divided into groups using cut-offs for categories of BMI. Data were assessed according to frequencies, measures of central tendency, Pearson correlations, chi-square tests, multiple regression and stratified actuarial analyses with log-rank tests for comparisons. The level of statistical significance was set at p = 0.05.

RESULTS

The number of obese patients increased significantly from immediately before heart transplant to 5 years later (17% vs 38%) (p < 0.0001). Risk factors for increased BMI at 1 year after heart transplant (explaining 56% of variance) included increased BMI at transplant, younger age, black race, non-ischemic etiology of heart disease, Status I at time of transplant and non-use of mycophenolate mofetil. Patients who were underweight or obese at 1 year post-transplant were at greater risk for rejection over time than patients who were of normal weight or overweight (p = 0.009).

CONCLUSIONS

Both demographic and clinical factors are related to increased BMI at 1 year after heart transplantation. Post-transplant cachexia and obesity are risk factors for poor clinical outcomes after heart transplantation.

Microalbuminuria and abnormal ambulatory blood pressure in adolescents with type 2 diabetes mellitus

OBJECTIVE

To determine whether risk factors for cardiovascular disease and diabetic nephropathy, as evidenced by abnormalities of ambulatory blood pressure (ABP), dyslipidemia, and microalbuminuria (MA), are present in adolescents with type 2 diabetes mellitus (T2DM).

STUDY DESIGN

We enrolled 26 minority adolescents recently diagnosed with T2DM and 13 obese control subjects without diabetes mellitus. ABP monitoring was performed, and a 24-hour urine, a fasting lipid profile, blood urea nitrogen, creatinine, homocysteine, and hemoglobin A 1 c levels were obtained. The patients with T2DM underwent echocardiograms.

RESULTS

Forty percent of the patients with T2DM had MA (> or = 30 mg of microalbumin/day), compared with none of the control subjects ( P < .05). There were no significant differences between patients with T2DM who had MA and patients with T2DM who didn't have MA in demographics, characteristics, casual BP, echocardiographic findings, and hemoglobin A 1 c levels. Average daytime systolic BP was greater in patients with T2DM with MA than patients without MA (129 versus 121 mm Hg, P = .03) and compared with the control subjects (113 mm Hg, P = .01). Patients with MA had an average daytime systolic BP load that was higher than patients without MA (37.1 versus 5.1%, P = .008) and compared with the control subjects (2.6%, P < .001).

CONCLUSION

As in adults, adolescents with T2DM exhibit abnormalities of ABP, dyslipidemia, and microalbuminuria.

Impact of body mass index on the outcome of patients with multivessel disease randomized to either coronary artery bypass grafting or stenting in the ARTS trial: The obesity paradox II?

The effect of body mass index (BMI) on outcomes after coronary artery revascularization remains controversial. We studied 1,203 patients who had multivessel coronary artery disease and underwent stenting (n = 599) or coronary artery bypass grafting (CABG; n = 604) in the Arterial Revascularization Therapies Study. Patients were assigned to 1 of 3 groups according to BMI: <25, 25 to 30, and >30 kg/m(2). At 3-year follow-up, the incidence of death, cerebrovascular events, or myocardial infarction was similar for these BMI categories regardless of the revascularization technique used. Rates of repeat revascularization procedures were significantly higher among patients who had been randomized to stenting but were similar across BMI groups. For patients who had been randomized to undergo CABG, there was a significant decrease in repeat revascularization procedures in obese patients (p = 0.03). Among patients who underwent stenting, BMI had no effect on the 3-year combined end point of rate of major adverse cardiac or cerebrovascular events. Among patients who underwent CABG, major adverse cardiac or cerebrovascular event rates were significantly lower for patients who were obese (11%) or overweight (16%) compared with patients who had a normal BMI (24%; p = 0.008). Thus, in a large cohort of patients who had multivessel coronary artery disease and underwent surgical or percutaneous revascularization, BMI had no effect on 3-year outcome of those who underwent stenting. Conversely, among patients who underwent CABG, those who were overweight or obese had a significantly better outcome than did those who had a normal BMI with regard to survival without major adverse cardiac or cerebrovascular events, mainly due to lower rates of repeat revascularization procedures.

Biliopancreatic diversion in the surgical treatment of morbid obesity

Biliopancreatic diversion is a malabsorptive technique of bariatric surgery that has gained wide acceptance in the Western world. It is performed in one of two ways: In its classic form it consists of partial gastrectomy with a Roux-en-Y gastroenterostomy; in its duodenal switch form a vertical sleeve gastrectomy is combined with a duodenoenterostomy. Both techniques realize diversion of biliopancreatic juice, thereby creating a mild form of malabsorption. Weight loss has been approximately 70% of initial excess weight, exceeding that obtained with most other bariatric procedures. Iron, calcium, and vitamin deficiencies may occur, especially with classic biliopancreatic diversion, and must be prevented with adequate supplements during vigorous follow-up. Weight loss is followed by a substantial reduction in the co-morbidities that are present in many morbidly obese patients. Biliopancreatic diversion should be included in each obesity clinic program and be proposed for morbidly obese patients who are having difficulty with the prospect of continuous restraint of food intake or problems due to failed gastric restrictive interventions. The postoperative results in such patients have been good and have substantially improved quality of life and self-esteem in this category of morbidly obese patients.

Aspartame: review of safety

Over 20 years have elapsed since aspartame was approved by regulatory agencies as a sweetener and flavor enhancer. The safety of aspartame and its metabolic constituents was established through extensive toxicology studies in laboratory animals, using much greater doses than people could possibly consume. Its safety was further confirmed through studies in several human subpopulations, including healthy infants, children, adolescents, and adults; obese individuals; diabetics; lactating women; and individuals heterozygous (PKUH) for the genetic disease phenylketonuria (PKU) who have a decreased ability to metabolize the essential amino acid, phenylalanine. Several scientific issues continued to be raised after approval, largely as a concern for theoretical toxicity from its metabolic components--the amino acids, aspartate and phenylalanine, and methanol--even though dietary exposure to these components is much greater than from aspartame. Nonetheless, additional research, including evaluations of possible associations between aspartame and headaches, seizures, behavior, cognition, and mood as well as allergic-type reactions and use by potentially sensitive subpopulations, has continued after approval. These findings are reviewed here. The safety testing of aspartame has gone well beyond that required to evaluate the safety of a food additive. When all the research on aspartame, including evaluations in both the premarketing and postmarketing periods, is examined as a whole, it is clear that aspartame is safe, and there are no unresolved questions regarding its safety under conditions of intended use.