The epidemiology of obesity

Diabesity: Were We are Wrong and What is the Cost?

Obesity, metabolic syndrome, prediabetes and dislipidemia are the major risk factors for developing type 2 diabetes and posible severe complications which can decrese quality of life and increase population mortality.

Due to its epidemic characteristic and high costs of care, diabetes became a major health problem around the world.

It is compulsory to know epidemiological data and possible evolution of diabetes to ensure rational health policies among risk population.

The effect of increasing body mass index on laparoscopic surgery for colon and rectal cancer

AIM

Obesity is common in Western countries and its prevalence is increasing. Colorectal cancer is common, and surgery for colorectal cancer is technically more challenging in obese patients. Laparoscopic surgery for colon cancer has been shown to be oncologically equivalent, with improved short- term outcomes. Laparoscopic surgery for rectal cancer has proven technically challenging, and recent results have raised concerns about oncological equivalence. Our aim was to evaluate the effect of body mass index (BMI) on the clinical and oncological outcomes of surgery for colorectal cancer, including the rate at which laparoscopic surgery is attempted and the rate at which laparoscopic surgery is converted to open surgery.

METHOD

A retrospective analysis of prospectively collected data from two tertiary institutions was performed. Data were obtained from the Cabrini Monash University colorectal neoplasia database for patients having surgical resection for colon and rectal cancers between 1 January 2010 and 30 June 2015. Surgical and medical complications, tumour recurrence and overall survival and laparoscopic surgery and conversion rates were investigated.

RESULTS

This large case series of 1464 patients undergoing elective surgery for colorectal cancer has demonstrated that an elevated BMI is associated with a lower likelihood of attempting laparoscopic surgery and a higher conversion rate to open surgery when laparoscopy is attempted. Conversion was 1.9 times more likely in obese patients with colon cancer and 4.1 times more likely in obese patients with rectal cancer. The critical BMI for colon cancer patients was > 35 kg/m² , and for rectal cancer patients > 30 kg/m² . Obesity is also associated with increased rates of surgical complications, including anastomotic leakage and wound complications. Pathological parameters, tumour recurrence and survival were not affected by elevated BMI.

CONCLUSION

In the surgical management of colorectal cancer, obesity is associated with a lower likelihood of laparoscopic surgery being attempted, a higher likelihood of conversion to open surgery when laparoscopic surgery is attempted, and a higher rate of surgical complications.

Association of pretreatment body mass index and survival in human papillomavirus positive oropharyngeal squamous cell carcinoma

BACKGROUND

Pretreatment body mass index (BMI) >25kg/m(2) is a positive prognostic factor in patients with head and neck cancer. Previous studies have not been adequately stratified by human papilloma virus (HPV) status or subsite. Our objective is to determine prognostic significance of pretreatment BMI on overall survival in HPV+ oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

This is a retrospective review of patients with HPV+ OPSCC treated between 8/1/2006 and 8/31/2014. Patients were stratified by BMI status (>/<25kg/m(2)). Univariate and multivariate analyses of survival were performed.

RESULTS

300 patients met our inclusion/exclusion criteria. Patients with a BMI >25kg/m(2) had a longer overall survival (HR=0.49, P=0.01) as well as a longer disease-specific survival (HR=0.43, P=0.02). Overall survival remained significantly associated with high BMI on multivariate analysis (HR=0.54, P=0.04).

CONCLUSIONS

Pre-treatment normal or underweight BMI status is associated with worse overall survival in HPV+ OPSCC.

Anthropometric predictive equations for estimating body composition

Background:

Precise and accurate measurements of body composition are useful in achieving a greater understanding of human energy metabolism in physiology and in different clinical conditions, such as, cardiovascular disease and overall mortality. Dual-energy x-ray absorptiometry (DXA) can be used to measure body composition, but the easiest method to assess body composition is the use of anthropometric indices. This study has been designed to evaluate the accuracy and precision of body composition prediction equations by various anthropometric measures instead of a whole body DXA scan.

Materials and Methods:

We identified 143 adult patients underwent DXA evaluation of the whole body. The anthropometric indices were also measured. Datasets were split randomly into two parts. Multiple regression analysis with a backward stepwise elimination procedure was used as the derivation set and then the estimates were compared with the actual measurements from the whole-body scans for a validation set. The SPSS version 20 for Windows software was used in multiple regression and data analysis.

Results:

Using multiple linear regression analyses, the best equation for predicting the whole-body fat mass (R² = 0.808) included the body mass index (BMI) and gender; the best equation for predicting whole-body lean mass (R² = 0.780) included BMI, WC, gender, and age; and the best equation for predicting trunk fat mass (R² = 0.759) included BMI, WC, and gender.

Conclusions:

Combinations of anthropometric measurements predict whole-body lean mass and trunk fat mass better than any of these single anthropometric indices. Therefore, the findings of the present study may be used to verify the results in patients with various diseases or diets.

Prediction of Percentage Body Fat in Rural Thai Population Using Simple Anthropometric Measurements

OBJECTIVE

To develop and validate sex-specific equations for predicting percentage body fat (%BF) in rural Thai population, based on BMI and anthropometric measurements.

RESEARCH METHODS AND PROCEDURES

%BF (DXA; GE Lunar Corp., Madison, WI) was measured in 181 men and 255 women who were healthy and between 20 and 84 years old. Anthropometric measures such as weight (kilograms), height (centimeters), BMI (kilograms per meter squared), waist circumference (centimeters), hip circumference (centimeters), thickness at triceps skinfold (millimeters), biceps skinfold (millimeters), subscapular skinfold (millimeters), and suprailiac skinfold (millimeters) were also measured. The sample was randomly divided into a development group (98 men and 125 women) and a validation group (83 men and 130 women). Regression equations of %BF derived from the development group were then evaluated for accuracy in the validation group.

RESULTS

The equation for estimating %BF in men was: %BF(men) = 0.42 x subscapular skinfold + 0.62 x BMI - 0.28 x biceps skinfold + 0.17 x waist circumference - 18.47, and in women: %BF(women) = 0.42 x hip circumference + 0.17 x suprailiac skinfold + 0.46 x BMI - 23.75. The coefficient of determination (R2) for both equations was 0.68. Without anthropometric variables, the predictive equation using BMI, age, and sex was: %BF = 1.65 x BMI + 0.06 x age - 15.3 x sex - 10.67 (where sex = 1 for men and sex = 0 for women), with R2 = 0.83. When these equations were applied to the validation sample, the difference between measured and predicted %BF ranged between +/-9%, and the positive predictive values were above 0.9.

DISCUSSION

These results suggest that simple, noninvasive, and inexpensive anthropometric variables may provide an accurate estimate of %BF and could potentially aid the diagnosis of obesity in rural Thais.

West African and Amerindian ancestry and risk of myocardial infarction and metabolic syndrome in the Central Valley population of Costa Rica

Genetic ancestry and environmental factors may contribute to the ethnic differences in risk of coronary heart disease (CHD), metabolic syndrome (MS) or its individual components. The population of the Central Valley of Costa Rica offers a unique opportunity to assess the role of genetic ancestry in these chronic diseases because it derived from the admixture of a relatively small number of founders of Southern European, Amerindian, and West African origin. We aimed to determine whether genetic ancestry is associated with risk of myocardial infarction (MI), MS and its individual components in the Central Valley of Costa Rica. We genotyped 39 ancestral informative markers in cases (n = 1,998) with a first non-fatal acute MI and population-based controls (n = 1,998) matched for age, sex, and area of residence, to estimate individual ancestry proportions. Odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated using conditional (MI) and unconditional (MS and its components) logistic regression adjusting for relevant confounders. Mean individual ancestry proportions in cases and controls were 57.5 versus 57.8% for the Southern European, 38.4 versus 38.3% for the Amerindian and 4.1 versus 3.8% for the West African ancestry. Compared with Southern European ancestry, each 10% increase in West African ancestry was associated with a 29% increase in MI, OR (95% CI) = 1.29 (1.07, 1.56), and with a 30% increase on the risk of hypertension, OR (95% CI) = 1.30 (1.00, 1.70). Each 10% increase in Amerindian ancestry was associated with a 14% increase on the risk of MS, OR (95% CI) = 1.14 (1.00, 1.30), and 20% increase on the risk of impaired fasting glucose, OR (95% CI) = 1.20 (1.01, 1.42). These results show that the high variability of admixture proportions in the Central Valley population offers a unique opportunity to uncover the genetic basis of ethnic differences on the risk of disease.

Can sibutramine alter systemic blood pressure in obese patients? Systematic review and meta-analysis

CONTEXT

Systemic arterial hypertension is part of the metabolic syndrome resulting from obesity.

OBJECTIVE

To evaluate the effect of sibutramine on overweight and obese patients' blood pressure through a systematic review.

METHODS

All the studies included needed to be randomized controlled trials. The methodological quality of the selected trials was assessed using the criteria described in the Cochrane Handbook. The participants were overweight and obese patients; the intervention was sibutramine compared with placebo. The primary outcome measurement was systolic and diastolic blood pressure and the secondary measurement was blood pressure. Studies were identified by searching the following sources: Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs), Medline, Cochrane reviews, manual searches, personal communication and contact with the pharmaceutical industry. There were no language, date or other restrictions. Data collection and extraction was performed by two reviewers, who independently obtained the full articles of all eligible papers.

RESULTS

Three meta-analyses were produced: 1) systolic blood pressure outcome (eight studies) did not show statistical significance between sibutramine and placebo: weighted mean difference (WMD) 1.57, confidence interval (CI) -0.03 to 3.18; 2) diastolic blood pressure outcome (ten studies) did not show statistical significance between sibutramine and placebo: WMD 1.13, CI -0.49 to 2.76; 3) blood pressure outcome (two studies) also did not show statistical significance between the groups: relative risk (RR) 0.69, CI 0.07 to 7.01.

CONCLUSIONS

The meta-analyses presented in this systematic review show that sibutramine does not have a statistically significant effect on blood pressure, compared with placebo.

Overweight and obesity in Portugal: national prevalence in 2003-2005

Obesity is an endemic health problem in most developed countries, requiring serious public health attention. The first Portuguese nationwide representative survey about obesity (with objective anthropometric measurement) was undertaken from 1995 to 1998. This paper presents data coming from the second and most recent nationwide representative study of obesity, with objective measurement of weight, height, waist and hip circumferences. Data were collected between January 2003 and January 2005. The survey collected objective body mass index (BMI) values of 8116 participants aged 18-64. Main findings were: 2.4% of the sample had low weight (BMI < 18.5), 39.4% were overweight (BMI between 25.0 and 29.9), and 14.2% obese (BMI > or = 30). Waist circumference measurement showed that 45.6% of the sample suffers increased cardiovascular health risks associated with high waist circumference. The overall overweight/obesity prevalence increased from 49.6% (in 1995-1998) to 53.6% (in 2003-2005). These data suggest that although obesity was identified as a public health problem one decade ago, action to reduce it does not seem to have been very effective to date. Well-defined public health intervention must be targeted to specific population groups where higher levels of obesity prevalence were found: low socioeconomic level groups and low-education level groups.

The influence of obesity on calf blood flow and vascular reactivity in older adults

OBJECTIVE

To determine whether differences in vascular reactivity existed among normal weight, overweight, and obese older men and women, and to examine the association between abdominal fat distribution and vascular reactivity.

METHODS

Eighty-seven individuals who were 60 years of age or older (age = 69 +/- 7 yrs; mean +/- SD) were grouped into normal weight (BMI < 25; n = 30), overweight (BMI > or = 25 and < 30; n = 28), or obese (BMI > or = 30; n = 29) categories. Calf blood flow (BF) was assessed by venous occlusion strain-gauge plethysmography at rest and post-occlusive reactive hyperemia.

RESULTS

Post-occlusive reactive hyperemia BF was lower (p = 0.038) in the obese group (5.55 +/- 4.67%/min) than in the normal weight group (8.34 +/- 3.89%/min). Additionally, change in BF from rest to post-occlusion in the obese group (1.93 +/- 2.58%/min) was lower (p = 0.001) than in the normal weight group (5.21 +/- 3.59%/min), as well as the percentage change (75 +/- 98% vs. 202 +/- 190%, p = 0.006, respectively). After adjusting for age, prevalence in hypertension and calf skinfold thickness, change in BF values remained lower (p < 0.05) in obese subjects compared to the normal weight subjects. Lastly, the absolute and percentage change in BF were significantly related to BMI (r = -0.44, p < 0.001, and r = -0.37, p < 0.001, respectively) and to waist circumference (r = -0.36, p = 0.001, and r = -0.32, p = 0.002).

CONCLUSION

Obesity and abdominal adiposity impair vascular reactivity in older men and women, and these deleterious effects on vascular reactivity are independent of conventional risk factors.

Coexistence of maternal central adiposity and child stunting in Mexico

OBJECTIVE

To assess the coexistence of maternal adiposity and child stunting (CS) in Mexico, estimate its national prevalence and identify the associated socio-demographic factors.

METHODS

A secondary analysis from the Mexican Nutrition Survey 1999, a nationally representative survey, was conducted. Mother and children subsamples were matched and a total of 6225 mother/child pairs were obtained. Stunting was defined as height-for-age z-scores <-2.0. Maternal body mass index (BMI) was classified according to World Health Organization recommended cutoff points. Waist-to-hip ratio (WHR) was calculated by dividing waist by hip circumferences. Logistic regression models were fitted to explore the coexistence of CS and maternal central adiposity (MCA) (WHR> or =0.85) while controlling for biological and socio-demographic factors.

RESULTS

A total of 5974 pairs had complete information. MCA coexisted with CS in 6.2% of the mother/child pairs. The phenomenon was more prevalent in rural locations, in the south region and among indigenous families (14.5, 12.5 and 23.9%). After controlling for child age and maternal BMI, a 78% increase in the likelihood of CS was related to maternal WHR > or =0.85 (odds ratio (OR)=1.78, 95% confidence interval (CI)=1.53, 2.10). After controlling for maternal height, the magnitude of the OR decreased (OR=1.33, 95%CI=1.13, 1.57), but remained significant. Therefore, it is suggested that women with a WHR approximately 1 have had twice the probability of having a stunted child as those with a WHR of 0.65.

CONCLUSION

Although MCA and CS are two conditions frequently regarded as result of opposite determinants, our observation suggests that this is not necessarily the case, particularly in populations undergoing the nutrition transition. MCA was associated not only to chronic diseases, but also to child stunting.

Development and implementation of a food store-based intervention to improve diet in the Republic of the Marshall Islands

Effective approaches for the prevention and reduction of obesity and obesity-related chronic diseases are urgently needed. Food store-centered programs represent one approach that may be both effective and sustainable. The authors developed a food store-based intervention in the Marshall Islands using qualitative and quantitative formative research methods, including a store usage survey (n = 184) and in-depth interviews with large-store managers (n = 13), small-store managers (n = 7), customers (n = 10), and community leaders (n = 4). This process was followed up by development and piloting of specific intervention components and workshops to finalize materials. The final intervention combined mass media (newspaper articles, video, radio announcements) and in-store components (shelf labels, cooking demonstrations, posters, recipe cards) and had high store-owner support and participation. High levels of exposure to the intervention were achieved during the 10-week period of implementation. This model for developing food store-based interventions is applicable to other settings.

Mapping by admixture linkage disequilibrium: advances, limitations and guidelines

Mapping by admixture linkage disequilibrium (MALD) is a theoretically powerful, although unproven, approach to mapping genetic variants that are involved in human disease. MALD takes advantage of long-range haplotypes that are generated by gene flow among recently admixed ethnic groups, such as African-Americans and Latinos. Under ideal circumstances, MALD will have more power to detect some genetic variants than other types of genome-wide association study that are carried out among more ethnically homogeneous populations. It will also require 200-500 times fewer markers, providing a significant economic advantage. The MALD approach is now being applied, with results expected in the near future.

Is obesity a risk factor for low back pain? An example of using the evidence to answer a clinical question

BACKGROUND: Obesity as a causal factor for low back pain has been controversial with no definitive answer to this date. The objective of this study was to determine whether obesity is associated with low back pain. In addition this paper aims to provide a step-by-step guide for chiropractors and osteopaths on how to ask and answer a clinical question using the literature. METHODS: A literature review using the MEDLINE search engine using the keywords "obesity", "low back pain", "body mass index" "BMI" and "osteoarthritis" from years 1990 to 2004 was utilised. The method employed is similar to that utilised by evidence-based practice advocates. RESULTS: The available data at this time is controversial with no clear-cut evidence connecting low back pain with obesity. CONCLUSION: There is a lack of a clear dose-response relationship between body mass index (BMI) and low back pain. Further, studies on the relationship between obesity and related lumbar osteoarthritis, knee pain, and disc herniation are also problematic.There is little doubt that future studies with controlled variables are needed to determine the existence of an unambiguous link, if any.

Effect of Metabolic Syndrome on Heart Attack and Mortality in Mexican-American Elderly Persons: Findings of 7-Year Follow-Up From the Hispanic Established Population for the Epidemiological Study of the Elderly

PURPOSE

We aim to examine the effect of Metabolic syndrome (MetS) on heart attack and overall mortality in Mexican-American elderly persons over 7-year follow-up.

METHODS

We studied 3050 Mexican Americans aged 65 or older from the Hispanic Established Population for the Epidemiological Study of the Elderly conducted in five Southwestern states of the United States. Participants were categorized into two groups: those with or without MetS. A total of 333 (11%) respondents at baseline had met the criteria of MetS (at least three of five characteristics--hyperinsulinemia or fasting plasma glucose > or =110 mg/dl, abdominal obesity, and hypertension--as defined by the World Health Organization).

RESULTS

Of 333 participants with MetS, the mean age was 71.1 years and 68% were females (compared with 73.2 years and 56% in those without MetS). Eighty percent of participants with MetS rated their health as fair or poor, compared to 55% of those participants without MetS. Fifty-four percent and 65% of patients with MetS had arthritis and at least one impairment in instrumental activities of daily living (IADL), compared to 39% and 55% of those participants without MetS. MetS was significantly associated with increased incidence of heart attack (odds ratio: 2.75, 95% confidence interval: 1.67-4.54) and was a significant predictor for overall mortality (hazard ratio: 1.46, 95% confidence interval: 1.16-1.84) over a 7-year period after adjusting for other demographic and clinical variables.

CONCLUSIONS

Among Mexican-American elderly participants, those with MetS had poorer self-rated health. MetS was significantly associated with increased incidence of heart attack and higher mortality over a 7-year period.

Measuring and using admixture to study the genetics of complex diseases

Admixture is an important evolutionary force that can and should be used in efforts to apply genomic data and technology to the study of complex disease genetics. Admixture linkage disequilibrium (ALD) is created by the process of admixture and, in recently admixed populations, extends for substantial distances (of the order of 10 to 20 cM). The amount of ALD generated depends on the level of admixture, ancestry information content of markers and the admixture dynamics of the population, and thus influences admixture mapping (AM). The authors discuss different models of admixture and how these can have an impact on the success of AM studies. Selection of markers is important, since markers informative for parental population ancestry are required and these are uncommon. Rarely does the process of admixture result in a population that is uniform for individual admixture levels, but instead there is substantial population stratification. This stratification can be understood as variation in individual admixtures and can be both a source of statistical power for ancestry-phenotype correlation studies as well as a confounder in causing false-positives in gene association studies. Methods to detect and control for stratification in case/control and AM studies are reviewed, along with recent studies showing individual ancestry-phenotype correlations. Using skin pigmentation as a model phenotype, implications of AM in complex disease gene mapping studies are discussed. Finally, the article discusses some limitations of this approach that should be considered when designing an effective AM study.

Diabetes, lipids, and adipocyte secretagogues

That obesity is associated with insulin resistance and type II diabetes mellitus is well accepted. Overloading of white adipose tissue beyond its storage capacity leads to lipid disorders in non-adipose tissues, namely skeletal and cardiac muscles, pancreas, and liver, effects that are often mediated through increased non-esterified fatty acid fluxes. This in turn leads to a tissue-specific disordered insulin response and increased lipid deposition and lipotoxicity, coupled to abnormal plasma metabolic and (or) lipoprotein profiles. Thus, the importance of functional adipocytes is crucial, as highlighted by the disorders seen in both "too much" (obesity) and "too little" (lipodystrophy) white adipose tissue. However, beyond its capacity for fat storage, white adipose tissue is now well recognised as an endocrine tissue producing multiple hormones whose plasma levels are altered in obese, insulin-resistant, and diabetic subjects. The consequence of these hormonal alterations with respect to both glucose and lipid metabolism in insulin target tissues is just beginning to be understood. The present review will focus on a number of these hormones: acylation-stimulating protein, leptin, adiponectin, tumour necrosis factor alpha, interleukin-6, and resistin, defining their changes induced in obesity and diabetes mellitus and highlighting their functional properties that may protect or worsen lipid metabolism.

Cognitive-behavioural guided self-help for obesity: a preliminary research

This study examined the effectiveness of the manual for obesity Perdere peso senza perdere la testa (Losing weight without losing your mind) used in form of guided self-help on 161 patients. Three levels of treatments were compared: (a) guided self-help treatment (GSH); (b) minimal guided self-help treatment (M-GSH); (c) control condition (CC). At the end of the treatment, a significant reduction in body weight was observed in GSH and M-GSH, but not in the CC. At six-month follow-up 32.7% of GSH subjects and 15.1% of M-GSH subjects were able to maintain at least a 5% weight loss. The findings show that GSH is more effective than M-GSH in determining a significant short-term reduction of body weight.

The effects of a 12-week group exercise programme on physiological and psychological variables and function in overweight women

OBJECTIVES

The aim of this study was to investigate the effect of a 12-week functional exercise programme on overweight women.

METHODS

Twenty-six subjects (n=13 exercisers, n=13 controls) aged (mean+/-SD) 63 (+/-4) years completed the study. The exercise sessions were carried out twice each week for 12 weeks. The variables measured were body mass, body mass index, skin-fold thickness, resting blood pressure, total blood cholesterol, chair rise, timed 'up and go' test, 20-m walk,lifting a 1- and a 2-kg bag on to a shelf, stair walking, 'sit and reach' flexibility test, Life Satisfaction Index and Physical Self-perception Profile for Older Adults. The exercise sessions consisted of 40-min sessions during which the subjects performed aerobic and strength exercises.

RESULTS

Paired analyses showed that body mass, body mass index, blood pressure (systolic and diastolic values), 'up and go' time, time to complete a 20-m walk, time to lift a 1- and a 2-kg bag with both the right and left arms onto a shelf, and stair climbing-total time and ascent time-decreased significantly in the exercise group. Also, the exercise group improved their Life Satisfaction Index score significantly compared with the control group.

CONCLUSIONS

The results indicate that a functional exercise programme has the potential to improve performance in a number of physiological variables and functional activities in overweight women. The exercise programme enhanced life satisfaction.

Self-reported heart attack in Mexican-American elders: examination of incidence, prevalence, and 7-year mortality

OBJECTIVES

To examine the prevalence, incidence, and mortality of self-reported heart attack in older Mexican Americans and to identify significant factors associated with heart attack.

DESIGN

Cross-sectional and longitudinal study.

SETTING

Baseline and three follow-up interviews in five southwestern states (Arizona, California, Colorado, New Mexico, and Texas) of the Hispanic Established Population for the Epidemiological Study of the Elderly.

PARTICIPANTS

Three thousand fifty Mexican Americans aged 65 to 107 (mean age = 73).

MEASUREMENTS

Sociodemographic factors (age, sex, marital status, language of interview, health insurance coverage, living arrangements, and financial strain) and health factors (smoking, alcohol consumption, obesity, diabetes mellitus, hypertension, stroke, cancer, hip fracture, arthritis, depression, limitations in activities of daily living (ADLs) and instrumental activities of daily living (IADLs), and mortality) were determined at baseline (1993-94). New heart attacks were assessed at follow-ups in 1995-96, 1998-99, and 2000-01. Vital status was determined over the 7-year follow-up.

RESULTS

Prevalence of self-reported heart attack was 9.1% at baseline. Incidence of self-reported heart attack was 6.1%, 9.1%, and 7.9%, respectively, for the three subsequent follow-ups. Older age, male sex, diabetes mellitus, hypertension, and stroke were significantly associated with heart attack at baseline. Age was a significant predictor for new heart attack at each follow-up. Having ADL (odds ratio (OR) = 2.91, 95% confidence interval (CI) = 2.19-3.86) and IADL (OR = 2.25, CI = 1.72-2.94) disabilities was significantly associated with self-reported heart attack. Subjects with heart attack were significantly more likely to die at 7 years (hazard ratio = 1.57, 95% CI = 1.29-1.91). Of those with self-reported heart attack, 42.4% had died of heart attack as the underlying cause of death by 7-year follow-up.

CONCLUSION

In Mexican Americans, self-reported heart attack was associated with being older and male and having diabetes mellitus, hypertension, stroke, and ADL and IADL disabilities. Nearly half of subjects with heart attack had died of heart attack as underlying cause of death by 7-year follow-up. Prevention and control for this disease would be especially important in this population to avoid early mortality.

Weight loss in combination with physical activity improves endothelial dysfunction in human obesity

OBJECTIVE

To test whether weight loss may improve endothelial dysfunction in human obesity, we recruited 28 healthy obese subjects, aged 30-46 years, with BMI 30-43 kg/m(2).

RESEARCH DESIGN AND METHODS

Endothelium-dependent and -independent vasodilation were investigated by intra-arterial infusion of increasing doses of acetylcholine (ACh; 7.5, 15, and 30 microg x ml(-1) x min(-1)) and sodium nitroprusside (0.8, 1.6, and 3.2 microg x ml(-1) x min(-1)). Insulin resistance was estimated by homeostasis model assessment (HOMA). Weight loss was obtained by caloric restriction and physical activity.

RESULTS

We observed a significant reduction in BMI (from 33.1 +/- 4.2 to 27.5 +/- 4.5 kg/m(2), -16.9%, P < 0.0001) and in waist circumference (from 108.2 +/- 12.1 to 96.8 +/- 12.9 cm, -10.5%, P < 0.0001). Weight loss was also associated with a significant increase in ACh-stimulated forearm blood flow (FBF), from 7.4 +/- 2.8 to 12.9 +/- 3.4 ml. 100 ml(-1) of tissue x min(-1) kg/m(2) (P < 0.0001). Multivariate regression analysis demonstrated that the only independent predictor of FBF was HOMA, accounting for 44.5% of the variation, whereas the addition of BMI explained another 2.3% of the variation.

CONCLUSIONS

Our data demonstrate that energy-restricted diet associated with physical activity induce a significant and clinically relevant improvement in ACh-stimulated vasodilation in obese healthy subjects.

Lower extremity amputations in diabetic Mexican American elders: incidence, prevalence and correlates

This study was designed to determine the incidence and prevalence of amputations in diabetic Mexican American elders and to identify correlates of lower extremity amputations. Data for this study came from baseline and two follow-up interviews of the Hispanic Established Population for the Epidemiological Study of the Elderly (EPESE) conducted in five southwestern states (Texas, California, New Mexico, Colorado and Arizona) in 1993-1994. Of the 3050 subjects aged 65 and older, 690 reported diabetes, and from these, 60 (8%) reported having at least one lower extremity amputation. Losing a leg was the most common type of amputation (53%). Twelve percent of respondents reported a new amputation and 40% of amputees reported a second amputation during follow-up. Mortality among amputees was 46% during a 5-year follow-up. Multiple logistic regression analysis showed that being male and having eye problems, hip fracture and diabetes for 10 or more years were significantly associated with lower extremity amputations at baseline, whereas obesity, stroke and 10 or more years with diabetes were significantly associated with new amputations at 5-year follow-up. Gender and disease history were associated with lower extremity amputations at baseline and follow-up. These variables may be useful in developing patient education and intervention programs.

The effect of obesity on renal transplant outcomes

BACKGROUND

Although obesity has been associated with improved survival on dialysis, its effects on renal transplant outcomes remain unclear. Previous studies have reported conflicting findings and have been limited by the use of outdated patient data, univariate analyses, and liberal transplant selection criteria. The present study aimed to evaluate the effect of obesity on renal transplant outcomes in a rigorously screened population.

METHODS

A retrospective analysis was undertaken of all patients transplanted at the Princess Alexandra Hospital from 1 April 1994 to 31 March 2000. Patients were rigorously screened for cardiovascular disease before acceptance for transplantation. The effects of obesity on renal transplant outcomes were assessed by logistic and multivariate Cox regressions.

RESULTS

Of the 493 patients transplanted, 59 (12%) were obese (body mass index [BMI] 30 kg/m ). Obese patients were more likely to experience superficial wound breakdown (14% vs. 4%, P<0.01) and complete wound dehiscence (3% vs. 0%, P<0.01). Wound infections also tended to be more frequent in obese recipients (15% vs. 8%, P=0.11). There were no significant differences between the two groups with respect to operative duration, postoperative complications, hospitalization, delayed graft function, or acute rejection episodes. Five-year actuarial survival rates were comparable between the two groups with respect to graft survival (83% vs. 84%, P=NS) and patient survival (91% vs. 91%, P=NS). On multivariate analysis, BMI was an independent risk factor for wound breakdown (odds ratio 1.21, 95% CI 1.09-1.34, P<0.001), but not for other posttransplant complications, hospitalization, graft loss, or patient survival.

CONCLUSIONS

The only significant adverse effect of obesity on renal transplant outcomes was an increase in wound complications, which were generally of minor consequence. Provided that adequate care is taken to avoid transplanting patients with significant cardiovascular disease, obese recipients can achieve excellent long-term patient and graft survivals that are on par with their nonobese counterparts. Denying patients access to renal transplantation on the basis of obesity per se does not appear to be justified.

Differences in body mass index and waist: hip ratios in North Indian rural and urban populations

Overweight could be a major factor in determining the increasing rates of coronary heart disease in the Indian population, by its influence on blood pressure, diabetes and insulin resistance. We studied the prevalence of overweight in north Indian urban and rural population samples. The urban sample population (n = 3050) was selected using a multistage sampling with stratification for geographical zone and the type of residential colony and cluster sampling of urban blocks in each stratum. The rural sample (n = 2487) was selected by random sampling of villages stratified for population size followed by coverage of all eligible persons in the village. All participating individuals were 35-64 years of age. Women constituted 52.2% (n = 1594) and 57% (n= 1417) of urban and rural samples, respectively. The study reveals that overweight is widely prevalent in the adult urban Delhi population, whereas underweight is a significant problem in the rural population. This was noted across all the age groups in both men and women. We estimated 'comprehensive coronary risk estimates' based on the New Zealand Heart foundation guidelines and noted that the proportion of high and very high risk subjects increased in a continuous manner even within the 'normal' ranges of BMI. This difference in prevalence in the urban population could represent the demographic transition in the Indian population.

The impact of obesity in renal transplantation: an analysis of paired cadaver kidneys

BACKGROUND

Previous studies indicate that obesity is a risk factor in renal transplantation. However, these analyses did not control for variable donor factors that may strongly influence outcome. To control for donor variables such as age, cause of death, procurement techniques, preservation methods, cold ischaemia time and implantation technique, we analysed patient and graft survival in recipients of paired kidneys, derived from the same procurement procedure, preserved in the same manner, subjected to similar cold ischaemia time and implanted by the same surgical team. Between June 1992 and August 1999, 28 procurement procedures provided kidneys which were transplanted into one obese and one non-obese recipient. Body mass index (BMI) was calculated as kg/m2. Recipients were classified as obese (BMI > 30) or non-obese (BMI < 30). Immunotherapy for all recipients consisted of a triple therapy regimen of cyclosporine or prograf, azathioprine or cellcept, and prednisone. Patients with delayed graft function (DGF), defined as the need for dialysis within 72 h of the transplant procedure, were treated with anti-thymocyte globulin (ATG) or thymoglobulin (TMG) induction for 5-7 d. The rate of DGF (7.1 versus 10.7%) and acute rejection (39.3 versus 35.7%) were similar in the obese and non-obese recipient groups. Patient survival was similar at 1, 3 and 5 yr in both groups. In addition, graft survival was similar at 1 yr. However, a trend toward decreased medium-term graft survival, which reached significance at 5 yr, was observed in the obese group. Furthermore, mean serum creatinine at 1 yr was higher in the obese group (2.0) compared with the non-obese group (1, 4) (p=0.12). This analysis of paired cadaver kidneys indicated that obesity is not a risk factor for DGF, acute rejection, and 1-yr graft survival. However, a decreased medium- and long-term graft survival trend, which reached statistical significance at 5 yr, was observed in obese recipients.

Increasing obesity among male workers in Japan: 1992-1997

OBJECTIVE

To examine changes in the Body Mass Index (BMI) and in the prevalence of obesity among male Japanese workers after five years.

DESIGN

Follow-up study, based on data from annual health checkups performed at workplaces.

SUBJECTS AND METHODS

We had access to the data for a total of 63,951 male workers aged 20 through 54 years in 1992 who were examined in both 1992 and 1997. In quinquennial cohorts, we compared the findings for mean BMI and the prevalence of obesity in 1992 with the findings in 1997.

RESULTS

Between 1992 and 1997, in all cohorts the mean BMI increased significantly. For each adjacent cohort pair the mean BMI value in 1997 was significantly higher than in 1992. In 1992, 21.3% of all subjects were obese, increasing by 3.4% after five years to 24.7% in 1997. In the younger 1968-1972 and 1963-1967 cohorts the prevalence of obesity increased by 6.3% during five years. The significant increase in the obesity prevalence was observed from 1992 to 1997 for each age-adjusted cohort.

CONCLUSIONS

These results suggest a substantial increase in obesity among male Japanese workers. The notable increase in the prevalence of obesity among young male adults and the general trend toward widespread obesity during five years signal an increasing risk of lifestyle-related diseases.

Obesity and undernutrition and cardiovascular risk factors in rural and urban Gambian communities

OBJECTIVES

This study documented the prevalence of and cardiovascular risk factors associated with obesity and undernutrition in the Gambia.

METHODS

Adults (> or =15 years; N = 5373) from rural and urban areas completed a questionnaire; their height, weight, and waist and hip circumferences were measured, and their cardiovascular risk factors were assessed.

RESULTS

Prevalence of undernutrition (body mass index < 18 kg/m(2)) was 18.0%; all strata of society were affected. Prevalence of obesity (body mass index > or =30 kg/m(2)) was 4.0% but was higher (32.6%) among urban women 35 years or older. Cardiovascular risk factors were more prevalent among obese participants.

CONCLUSIONS

Undernutrition coexists with obesity, demonstrating a "double burden of disease." Differential interventions should focus on high-risk groups; prevention needs a multisectorial approach.

Human obesity: an evolutionary approach to understanding our bulging waistline

The unique worldwide spread of the human species and the remarkably long post-reproductive survival show that our genome permits excellent adaptation to vastly different environments. Moreover, the main scourges of later age, namely malignant growths and atherosclerosis, appear in humans later than in shorter-living animals. In recent years, excess weight and obesity have become mass phenomena with a pronounced upward trend in all developed countries. However, despite the detrimental effects of being overweight, these populations live longer than ever, which in part may be explained by the availability of better medical treatment. The prevalence and predicted further spread of obesity can be understood in the light of evolution. In all animal species energy metabolism is asymmetric with energy accumulation ('thrifty genotype') being the necessary condition of survival during hard times. For humans, which are no different to other animals in this respect, this genetic programming was necessary for survival because during the course of history, including the recorded history in the more developed Middle East, Europe or China, there was never a long period of uninterrupted food abundance, whereas famines were regular and frequent. Therefore fat accumulation, when food was available, meant survival at times of shortage, while the possible detrimental effects of overindulgence in food and being overweight expressed in unrealistically old age were irrelevant. It is the central, mostly intra-abdominal fat (in both humans and animals) that is more medically important than the subcutaneous truncal fat, and the accumulation of both types of fat is conditioned by high food consumption; therefore it is a historic novelty for human populations. In contrast, lower-body fat in human females is unique in the animal kingdom: it is much less metabolically active, it is of much lower pathologic significance than central fat, and it is programmed to be mobilized mostly during pregnancy and lactation. In view of all this, norms of desired weight should be based on hard mortality and morbidity statistics and not on theoretical, esthetic or fashion considerations. By this criterion, the upper limit of desirable weight is likely to be body mass index (BMI) 27 or 28, but specified for different populations (sex, race, ethnic origin); moreover, with aging, the detrimental effects of obesity diminish and finally disappear. Risks of other pathologies related to obesity (e.g. diabetes, hypertension and coronary disease) are also population-specific. However, total fatness, measured by BMI, is insufficiently sensitive as a risk factor, and fat distribution (upper-body versus low-body type, as reflected by waist circumference and waist:hip ratio) plays at least as prominent a role. Therefore the detailed norms, not yet available, should take into account both general obesity and fat distribution and be specific for different populations. Since long-term weight loss in adults is rarely achievable, public health measures should be aggressively directed at the prevention of obesity from childhood.

Salivary cortisol and DHEA: association with measures of cognition and well-being in normal older men, and effects of three months of DHEA supplementation

Dehydroepiandrosterone (DHEA) is a steroid that shows a marked age-related decline in humans. Previous research suggests potential for DHEA replacement in old age to enhance cognition and well-being. We conducted a clinical trial to test these hypotheses in a non-clinical sample of 46 men aged 62-76. Participants received either 50 mg DHEA daily for 13 weeks, followed by placebo for 13 weeks, or the reverse, in a randomised double-blind cross-over trial design. Levels of salivary cortisol and DHEA were measured at 0800 h and 2000 h prior to each assessment session. Cognition was assessed with tests of speed, attention and episodic memory. Well-being was measured with questionnaires of mood and perceived health. Mood questionnaires were completed at the assessment session as well as concurrently with saliva sampling.A correlational analysis of baseline behavioural data with hormonal data, controlling for age, revealed that higher morning DHEA was associated with lower confusion (r=-0.33; P=0.04), while higher evening DHEA was associated with lower anxiety (r=-0.35; P=0.03) and lower current negative mood in the morning (r=-0.37; P=0.03). Conversely, higher morning cortisol and a morning cortisol/DHEA ratio were associated with higher anxiety (r=0.35; P=0.03), (r=0.46; P=0.004), general mood disturbance (r=0.32; P=0.046), (r=0.32; P=0.04) and higher current negative mood in the evening (r=0.37; P=0.03), (r=0.38; P=0.03). A higher morning cortisol/DHEA ratio was also associated with higher confusion (r=0.39; P=0.01) and lower visuo-spatial memory performance (r=-0.39; P=0.01). Unexpectedly, higher evening cortisol was associated with faster choice reaction time (r=-0.33; P=0.04). These findings are consistent with an impairing effect of high cortisol on episodic memory and mood in older men, which may be attenuated by DHEA. When treatment effects were analysed, no significant effects of DHEA were observed on any of the trial outcomes, providing no support for benefits of DHEA supplementation for cognition or well-being in normal older men in the shorter-term.

A nutrition and exercise intervention program for controlling weight in Samoan communities in New Zealand

OBJECTIVE

To promote weight loss in Samoan church communities through an exercise program and nutrition education.

METHODS

A quasi-experimental design was used to assess weight change, over 1 y, in cohorts of people aged 20-77 y from three non-randomised Samoan church communities (two intervention, n=365 and one control, n=106) in Auckland, New Zealand. The intervention churches received aerobics sessions and nutrition education about dietary fat.

RESULTS

Baseline body mass index for the intervention and control churches was (mean+/-s.e.) 34.8+/-0.4 and 34.3+/-0.9 kg/m(2), respectively. The intervention churches lost an average of 0.4+/-0.3 kg compared to a 1.3+/-0.6 kg weight gain in the control church (P=0.039, adjusted for confounders). The number of people who were vigorously active increased by 10% in the intervention churches compared to a 5% decline in the control church (P=0.007). Nutrition education had little apparent impact on knowledge or behaviour.

CONCLUSION

Samoan communities in New Zealand are very obese and have high rates of annual weight gain. A community-based intervention program arrested this weight gain in the short term.

Body fat determination by dual energy X-ray absorptiometry and its relation to body mass index and waist circumference in Hong Kong Chinese

OBJECTIVE

To determine the relationship between percent body fat and body mass index (BMI) in the Chinese population of Hong Kong and to investigate whether the newly proposed lower BMI cut-offs for obesity in the Asia-Pacific Region recommended jointly by the International Association for the Study of Obesity, the International Obesity Task Force and the WHO are appropriate for Hong Kong Chinese.

METHODS

A total of 190 female and 140 male healthy subjects were recruited from the community. BMI was calculated as weight/height(2). Body fat content (%BF) was measured by dual-energy X-ray absorptiometry (DEXA).

RESULTS

Comparing %BF measured by DEXA with predicted %BF derived from BMI using a prediction formula developed in Caucasian population showed that the formula significantly under-predicted %BF by 1.1% in males and 3.4% in females. A predicted BMI of 25 and 30 kg/m(2) using a Caucasian-based formula corresponds to an actual BMI of 23 and 25 kg/m(2), respectively. On linear regression analysis, 25% BF corresponds to a BMI of 24.6 kg/m(2) in males and a waist circumference of 86 cm; 35% BF corresponds to a BMI of 22.6 kg/m(2) and a waist circumference of 73.5 cm in females.

CONCLUSION

Hong Kong Chinese population have a higher %BF for a given BMI which would partly explain why the health risks associated with obesity occur at a lower BMI. Our results would support the recommendations of using lower BMI cut-offs to define obesity in the Asia Region.

Lower BMI cut-off value to define obesity in Hong Kong Chinese: an analysis based on body fat assessment by bioelectrical impedance

There is increasing evidence suggesting that the cut-off values for defining obesity used in the Western countries cannot be readily applied to Asians, who often have smaller body frames than Caucasians. We examined the BMI and body fat (BF) as measured by bioelectrical impedance in 5153 Hong Kong Chinese subjects. We aimed to assess the optimal BMI reflecting obesity as defined by abnormal BF in Hong Kong Chinese. Receiver operating characteristic curve (ROC) analysis was used to assess the optimal BMI predicting BF at different levels. The mean age and SD of the 5153 subjects (3734 women and 1419 men) was 51.5 (SD 16.3) years (range: 18.0-89.5 years, median: 50.7 years). Age-adjusted partial correlation (r) between BMI and BF in women and men were 0.899 (P < 0.001) and 0.818 (P < 0.001) respectively. Using ROC analysis, the BMI corresponding to the conventional upper limit of normal BF was 22.5-23.1 kg/m(2), and the BMI corresponding to the 90 percentiles of BF was 25.4-26.1 kg/m(2). Despite similar body fat contents, the BMI cut-off value used to define obesity in Hong Kong Chinese should be lower as compared to Caucasians. We suggest a BMI of 23 kg/m(2) and 26 kg/m(2) as the cut-off values to define overweight and obesity respectively in Hong Kong Chinese.

Effects of dietary restriction on insulin resistance in obese mice

In many cases, development of insulin resistance has been linked to obesity and may contribute to mechanism of aging. The role of diet, irrespective of degree of obesity, in modulating insulin resistance and development of age degeneration disease remains uncertain. Lowered blood glucose levels are commonly associated with diet restriction (DR), which is an intervention shown to successfully retard aging and age associated disease. The effects of DR on blood glucose and insulin resistance were measured in yellow obese (A(vy)/A), lean black (a/a) mice and in another common inbred strain (B6C3F1) (at three different ages). The yellow obese mice become diabetic as a result of an insulin receptor defect which is not clearly understood. Insulin responses and radioinsulin binding were assayed in yellow obese and lean black mice fed either ad libitum (AL) or DR diets (YAL, BAL, YDR and YAL, respectively) at four different circadian intervals. The B6C3F1 controls were fed either AL (CAL) or DR (CDR) and measures were made at six circadian stages and three different ages. Within 23 days, DR produced a significant loss in body weight and a time-dependent 22-55% reduction in basal blood glucose levels in the yellow obese mice. Additionally, exogenous insulin produced circadian stage dependent (at the time of food intake) reductions in blood glucose in the YDR animals that were not present in YAL animals. (125)I-Insulin binding in liver was increased nearly 2-fold in YDR and BDR mice during the time of day that animals were active and eating. (125)I-Insulin binding was two-fold-higher in CDR mice at 4, 12 and >24 months of age. Binding decreased as a function of age in both the CAL and CDR animals. However, even in the >24 month group the CDR animals were found to have levels of binding that were as high as those found in younger CAL liver. The mechanism of action appears to be through resolution of insulin resistance by modulating an insulin receptor defect.

Changes in blood pressure and risk factors for cardiovascular disease among older Mexican-Americans from 1982-1984 to 1993-1994

OBJECTIVE

To determine the 10-year changes in blood pressure and cardiovascular risk factors among older Mexican-Americans.

DESIGN

Comparative analyses of the Hispanic Health and Nutrition Examination Survey (HHANES) and the Hispanic EPESE (Established Populations for Epidemiologic Studies of the Elderly). Both of these were population-based studies using a multistage stratified probability sampling design of noninstitutionalized persons.

SETTING

Five US states in the southwest: Arizona, California, Colorado, New Mexico, and Texas.

PARTICIPANTS

A total of 216 Mexican-Americans aged 65 to 74 from the 1982-1984 HHANES and 3050 Mexican-Americans aged 65+ from the 1993-1994 Hispanic EPESE.

MEASUREMENTS

Mean systolic and diastolic blood pressure; cigarette smoking; high levels of alcohol use; body mass index and obesity; self-reported heart attack, stroke, and diabetes; hypertension.

RESULTS

Among 65- to 74-year-old Mexican-Americans, there was a decrease over time in the percent of those who smoked cigarettes from 27.60% to 13.96% and a decrease in mean systolic blood pressure level. The percent of subjects categorized as obese or severely obese increased significantly, as did the prevalence of diagnosed diabetes, increasing from 20.06% in 1982-1984 to 29.82% in 1993-1994. Mean diastolic blood pressure increased from 77.15 mm Hg in 1982-1984 to 81.21 mm Hg in 1993-1994.

CONCLUSIONS

Our findings suggest major changes in cardiovascular risk factors between 1982-1984 and 1993-1994 among older Mexican-Americans.

Leptin suppression of insulin secretion and gene expression in human pancreatic islets: implications for the development of adipogenic diabetes mellitus

Previously we demonstrated the expression of the long form of the leptin receptor in rodent pancreatic beta-cells and an inhibition of insulin secretion by leptin via activation of ATP-sensitive potassium channels. Here we examine pancreatic islets isolated from pancreata of human donors for their responses to leptin. The presence of leptin receptors on islet beta-cells was demonstrated by double fluorescence confocal microscopy after binding of a fluorescent derivative of human leptin (Cy3-leptin). Leptin (6.25 nM) suppressed insulin secretion of normal islets by 20% at 5.6 mM glucose. Intracellular calcium responses to 16.7 mM glucose were rapidly reduced by leptin. Proinsulin messenger ribonucleic acid expression in islets was inhibited by leptin at 11.1 mM, but not at 5.6 mM glucose. Leptin also reduced proinsulin messenger ribonucleic acid levels that were increased in islets by treatment with 10 nM glucagon-like peptide-1 in the presence of either 5.6 or 11.1 mM glucose. These findings demonstrate direct suppressive effects of leptin on insulin-producing beta-cells in human islets at the levels of both stimulus-secretion coupling and gene expression. The findings also further indicate the existence of an adipoinsular axis in humans in which insulin stimulates leptin production in adipocytes and leptin inhibits the production of insulin in beta-cells. We suggest that dysregulation of the adipoinsular axis in obese individuals due to defective leptin reception by beta-cells may result in chronic hyperinsulinemia and may contribute to the pathogenesis of adipogenic diabetes.

Leptin suppression of insulin secretion and gene expression in human pancreatic islets: implications for the development of adipogenic diabetes mellitus

Previously we demonstrated the expression of the long form of the leptin receptor in rodent pancreatic beta-cells and an inhibition of insulin secretion by leptin via activation of ATP-sensitive potassium channels. Here we examine pancreatic islets isolated from pancreata of human donors for their responses to leptin. The presence of leptin receptors on islet beta-cells was demonstrated by double fluorescence confocal microscopy after binding of a fluorescent derivative of human leptin (Cy3-leptin). Leptin (6.25 nM) suppressed insulin secretion of normal islets by 20% at 5.6 mM glucose. Intracellular calcium responses to 16.7 mM glucose were rapidly reduced by leptin. Proinsulin messenger ribonucleic acid expression in islets was inhibited by leptin at 11.1 mM, but not at 5.6 mM glucose. Leptin also reduced proinsulin messenger ribonucleic acid levels that were increased in islets by treatment with 10 nM glucagon-like peptide-1 in the presence of either 5.6 or 11.1 mM glucose. These findings demonstrate direct suppressive effects of leptin on insulin-producing beta-cells in human islets at the levels of both stimulus-secretion coupling and gene expression. The findings also further indicate the existence of an adipoinsular axis in humans in which insulin stimulates leptin production in adipocytes and leptin inhibits the production of insulin in beta-cells. We suggest that dysregulation of the adipoinsular axis in obese individuals due to defective leptin reception by beta-cells may result in chronic hyperinsulinemia and may contribute to the pathogenesis of adipogenic diabetes.

Relationship between obesity and the increased risk of major complications in non-insulin-dependent diabetes mellitus

Obesity and non-insulin-dependent diabetes mellitus (NIDDM) are closely linked. They frequently occur together in patients, and body mass index (BMI) is the strongest risk factor for the development of NIDDM. Both obesity and NIDDM are also major causes of morbidity and mortality from atherogenic macrovascular disease, and they are independent risk factors for coronary heart disease. The risk of developing NIDDM and cardiovascular disease is affected by the regional distribution of body fat. Visceral obesity is associated with a higher degree of risk than peripheral obesity. The metabolic and circulatory changes associated with visceral obesity lead to the development of insulin resistance and increased lipoprotein synthesis. For example, the change in the population profile of lipoproteins in the blood, and alterations in the levels of oxidative stress lead to an increased cardiovascular and macrovascular risk. The changes in lipid metabolism also affect haemorrheological function. They have been linked to decreased fibrinolysis (a serious cardiovascular risk factor) through elevated levels of plasminogen activator inhibitor factor, high blood viscosity, and increased erythrocyte aggregability. Increased BMI also appears to be associated with endothelial dysfunction, which is a major factor in atheroma plaque formation and development of thrombosis. Visceral obesity therefore adds a significant burden to the already increased cardiovascular risk inherent in NIDDM. However, even moderate weight loss may successfully reverse the majority of changes seen with visceral obesity.

Secular trends of weight, height and obesity in cohorts of young Portuguese males in the District of Lisbon: 1960-1990

OBJECTIVE

To examine the secular trend of weight, height and obesity among young Portuguese males at the time of military inspection for national conscription purposes in the region of Lisbon, during the last thirty years.

DESIGN

Cross-sectional study, based on the review of military census files.

SETTING

Military selection centre of Lisbon.

SUBJECTS AND METHODS

In Portugal, military service is obligatory and medical inspections are carried out every year on males at the age of twenty. For study purposes, representative samples were taken from the young male population undergoing inspection for the Armed Forces on a five year basis, between 1960 and 1990 in the region of Lisbon. Weight and height were evaluated by a trained team, using standard measurement instruments and procedures.

RESULTS

A progressive and significant increase in weight, height and BMI of the young male population was found between 1960 and 1990. For certain variables the increase was also statistically significant within a five-year period, as it was the case for height between 1965-1980 and for weight between 1985-1990. The increase in BMI experienced some minor fluctuation along the reference period, however, it was statistically significant between 1985-1990. The increase in weight and in BMI was greater in the highest percentiles and particularly noticeable between 1985 and 1990. The percentage of young males with BMI over 25 kg/m2 was of 8.1% in 1960 and of 18.0% in 1990, while those having a BMI over 27 kg/m2 varied between 3.6% and 6.4% in the same period, respectively. The percentage of young adult males with BMI higher than 25 kg/m2 doubled between 1960 and 1990.

Acarbose treatment in obesity: a controlled study

Acarbose is an alpha-glucosidase inhibitor which reversibly inhibits oligosaccharidase and disaccharidase at the brush border of the small intestine. The aim of this study was to observe its effectiveness in the treatment of obesity.

METHODS

Two groups of 25 obese women were put on a 15 kcal/kg/day low-calorie diet for 12 weeks. One group (the study group) received 150 mg/day acarbose for the first 2 weeks and 300 mg/day acarbose for the remaining 10 weeks. The second group (controls) received no additional treatment. Body weight, BMI, skinfold thickness, serum lipids, OGTT, and insulin and C-peptide responses to OGTT were assessed before and after the study.

RESULTS

Body weight, BMI and skinfold thickness decreased significantly in both groups. Basal insulin and triglyceride levels in the study group, total and LDL cholesterol and triglyceride levels in the control group decreased significantly. No difference was found between the two groups when these decrements were compared, but the triglyceride level fell more in the control group.

CONCLUSION

Additional acarbose therapy is not more beneficial than low-calorie diet therapy alone.

The effect of age on cardiovascular risk factors in Chinese women

Chinese women traditionally have a low incidence of coronary heart disease. However, information on cardiovascular risk factors in this population are relatively scarce. We examined these risk factors in 601 Hong Kong Chinese women (age+/-SEM, 38.5+/-0.4 years; range, 18-66 years) stratified into four age groups (group 1, < or =30 years; group 2, 31-40 years; group 3, 41-50 years; group 4, > or =51 years). Increasing age in Chinese women was associated with increased body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, fasting plasma total cholesterol, triglyceride, low-density lipoprotein, apolipoprotein B, fasting and 2-h plasma glucose, glycated haemoglobin, fasting plasma insulin and urate concentrations. After adjustment for body mass index, waist-to-hip ratio and smoking, all these age-related associations remained statistically significant except for fasting plasma insulin concentration. There was a progressive increase with age in the prevalence of glucose intolerance, hypertension, dyslipidaemia and obesity. These prevalence rates further increased in subjects aged 51 years (the mean menopausal age in Asian women) or above. These findings suggest that age had an important and independent effect on cardiovascular risk in Chinese women and that, as in Caucasians, the onset of menopause might further increase this risk.

Should obese patients lose weight before receiving a kidney transplant?

BACKGROUND

The results of renal transplantation in obese recipients have been controversial, with some reports finding increased morbidity prohibitive and others finding increased morbidity acceptable. We attempted to determine whether obese patients in extreme excess of their ideal body weight should undergo transplantation.

METHODS

The study population included 127 obese (body mass index >30 kg/m2) patients who were compared with a matched nonobese control group (body mass index <27 kg/m2) of 127 recipients with similar demographics. There were no significant differences between the groups according to donor source, recipient race or sex, retransplants, transplant percent reactive antibodies, cause of renal failure, or hypertension. However, significantly more obese patients had a pretransplant history of angina (11.2% vs. 3.2%, P=0.02) or a previous myocardial infarction (5.6% vs. 0.8%, P=0.04).

RESULTS

The mean follow-up was 58.9+/-40 (range 3-170) months. Nonobese patients enjoyed a significantly (P=0.0002) greater patient survival (89% vs. 67%) at 5 years and suffered only about half the number of deaths (25 vs. 46) during the period of observation. Cardiac disease was the leading cause of death (39.1%) in the obese group. Patient death had a major impact on graft survival because there were no differences between the groups when death with graft function was censored from the analysis. There were no significant differences between the groups in delayed graft function, acute rejection, chronic rejection, length of hospital stay, operative blood loss, or mean serum creatinine up to 5 years. However, obese patients experienced significantly (P=0.0001) more complications per patient (3.3 vs. 2.2) and a greater incidence (P=0.0003) of posttransplant diabetes (12% vs. 2%). Similar cyclosporine blood levels were observed in obese recipients even though they were receiving 0.75-2 mg/kg/day less cyclosporine than the nonobese recipients.

CONCLUSIONS

Outcome differences in obese renal transplant patients were primarily due to a higher mortality resulting from cardiac events. Obesity seems to have little effect on immunologic events, long-term graft function, or cyclosporine delivery. Aggressive pretransplant screening for ischemic heart disease is essential to identify an especially high-risk subgroup of obese patients. Although it would seem prudent to recommend weight reduction <30 kg/m2 to all patients before transplant, these data suggest that obese patients with a history of cardiac disease should not be transplanted until weight reduction has been accomplished.

Genomic structure and promoter analysis of the human obese gene

The human gene encoding the homolog of the mouse obese (ob) gene was isolated and partially characterized. The human ob gene consists of three exons and two introns and spans about 18 kilobase pairs (kb), encoding a 3.5-kb cDNA. A 3-kb 5'-flanking region of the gene was cloned and transient transfection assay with luciferase reporter confirmed the promoter activity in differentiated F442-A adipocytes. Potential regulatory elements are discussed in this report.