Obesity over the life course

Health Patterns across Adulthood: An Age-Based Investigation of the Nutritional Status, Homocysteine, and CoQ10 of Bank Staff

BACKGROUND

This study aimed to evaluate age-specific variations in the blood levels of micronutrients, homocysteine, and CoQ10, along with physical activity (PA) patterns, among 123 Austrian adult bankers in operational and frontline roles (mean age: 43 years; 50% female).

METHODS

Blood analysis was conducted to assess micronutrients and the serum concentrations of homocysteine and CoQ10. The micronutrient values in whole blood were compared to sex-specific reference ranges and categorized as below, within, or above them. The Global Physical Activity Questionnaire was utilized to assess PA patterns. Participants were classified as young adults (18-34 years), middle-aged adults (35-49 years), and older adults (50-64 years).

RESULTS

Significant age-based differences were found in participants' mean homocysteine levels (p = 0.039) and homocysteine categories (p = 0.034), indicating an increasing prevalence of hyperhomocysteinemia with age. No significant difference between age categories was observed for sex, BMI, diet types, PA levels, sedentary behavior, and CoQ10 (p > 0.05). There was no significant age-based difference in the blood concentrations of most minerals and vitamins (p > 0.05), except for magnesium among females (p = 0.008) and copper among males (p = 0.042).

CONCLUSION

The findings offer initial evidence of the age-related differences in the health status of adult bankers, providing insights for customized approaches to occupational health that support the importance of metabolic health and overall well-being across adulthood.

The Prevalence of Weight Gain After Obtaining Employment: A Cross-Sectional Survey of Employees at the Ministry of National Guard Health Affairs, Eastern Region, Saudi Arabia

Background and objective Even though obesity is a major global health concern, few studies in the literature have discussed obesity in the workplace. In light of this, we aimed to explore obesity in the workplace and its contributing factors. Methodology An online survey was distributed via official work emails. The survey assessed demographic variables and work environment-related factors, such as physical and mental well-being, lack of time, and social and personal habits. The total sample included 380 full-time employees, of which 16.67% were excluded for not meeting the inclusion criteria. Data were analyzed by using descriptive and inferential statistics. Results Of note, 79.87% of the participants reported an increase in weight after getting employed. The average weight gain was 10.4 kg for 8.2 years of experience. The physical and mental items and time-related items had the highest average scores of 3.24 and 3.44, respectively. The multivariable logistic regression showed a significant association between work experience (p = 0.0259) and time (p = 0.0363), as well as physical and mental domains (p = 0.0007). Conclusions Based on our findings, greater work experience, a lack of time, and negative mental and physical well-being are risk factors for weight gain among employees.

The Role of Cdc42 in the Insulin and Leptin Pathways Contributing to the Development of Age-Related Obesity

Age-related obesity significantly increases the risk of chronic diseases such as type 2 diabetes, cardiovascular diseases, hypertension, and certain cancers. The insulin-leptin axis is crucial in understanding metabolic disturbances associated with age-related obesity. Rho GTPase Cdc42 is a member of the Rho family of GTPases that participates in many cellular processes including, but not limited to, regulation of actin cytoskeleton, vesicle trafficking, cell polarity, morphology, proliferation, motility, and migration. Cdc42 functions as an integral part of regulating insulin secretion and aging. Some novel roles for Cdc42 have also been recently identified in maintaining glucose metabolism, where Cdc42 is involved in controlling blood glucose levels in metabolically active tissues, including skeletal muscle, adipose tissue, pancreas, etc., which puts this protein in line with other critical regulators of glucose metabolism. Importantly, Cdc42 plays a vital role in cellular processes associated with the insulin and leptin signaling pathways, which are integral elements involved in obesity development if misregulated. Additionally, a change in Cdc42 activity may affect senescence, thus contributing to disorders associated with aging. This review explores the complex relationships among age-associated obesity, the insulin-leptin axis, and the Cdc42 signaling pathway. This article sheds light on the vast molecular web that supports metabolic dysregulation in aging people. In addition, it also discusses the potential therapeutic implications of the Cdc42 pathway to mitigate obesity since some new data suggest that inhibition of Cdc42 using antidiabetic drugs or antioxidants may promote weight loss in overweight or obese patients.

Obesity Risk of Pediatric Central Nervous System Tumor Survivors: A Cross-Sectional Study

Adult survivors of pediatric central nervous system (CNS) tumors are at the highest risk for morbidity and late mortality among all childhood cancers due to a high burden of chronic conditions, and environmental and lifestyle factors. This study aims to epidemiologically characterize young adult survivors of pediatric CNS tumors using body mass index (BMI) to assess risk factors for obesity. Using a cross-sectional design, young adults (18-39 years) previously treated for pediatric CNS tumors and followed in a survivorship clinic during 2016-2021 were examined. Demographic, BMI, and diagnosis information were extracted from medical records of the most recent clinic visit. Data were assessed using a two-sample t-test, Fisher's exact test, and multivariable logistical regression. 198 survivors (53% female, 84.3% White) with a BMI status of underweight (4.0%), healthy weight (40.9%), overweight (26.8%), obesity (20.2%), and severe obesity (8.1%) were examined. Male sex (OR, 2.414; 95% CI, 1.321 to 4.414), older age at follow-up (OR, 1.103; 95% CI, 1.037 to 1.173), and craniopharyngioma diagnosis (OR, 5.764; 95% CI, 1.197 to 27.751) were identified as significant (p < 0.05) obesity-related (≥25.0 kg/m²) risk factors. The majority of patients were overweight or obese. As such, universal screening efforts with more precise determinants of body composition than BMI, risk stratification, and targeted lifestyle interventions are warranted during survivorship care.

A foresight whole systems obesity classification for the English UK biobank cohort

Background

The number of people living with obesity or who are overweight presents a global challenge, and the development of effective interventions is hampered by a lack of research which takes a joined up, whole system, approach that considers multiple elements of the complex obesity system together. We need to better understand the collective characteristics and behaviours of those who are overweight or have obesity and how these differ from those who maintain a healthy weight.

Methods

Using the UK Biobank cohort we develop an obesity classification system using k-means clustering. Variable selection from the UK Biobank cohort is informed by the Foresight obesity system map across key domains (Societal Influences, Individual Psychology, Individual Physiology, Individual Physical Activity, Physical Activity Environment).

Results

Our classification identifies eight groups of people, similar in respect to their exposure to known drivers of obesity: ‘Younger, urban hard-pressed’, ‘Comfortable, fit families’, ‘Healthy, active and retirees’, ‘Content, rural and retirees’, ‘Comfortable professionals’, ‘Stressed and not in work’, ‘Deprived with less healthy lifestyles’ and ‘Active manual workers’. Pen portraits are developed to describe the characteristics of these different groups. Multinomial logistic regression is used to demonstrate that the classification can effectively detect groups of individuals more likely to be living with overweight or obesity. The group identified as ‘Comfortable, fit families’ are observed to have a higher proportion of healthy weight, while three groups have increased relative risk of being overweight or having obesity: ‘Active manual workers’, ‘Stressed and not in work’ and ‘Deprived with less healthy lifestyles’.

Conclusions

This paper presents the first study of UK Biobank participants to adopt this obesity system approach to characterising participants. It provides an innovative new approach to better understand the complex drivers of obesity which has the potential to produce meaningful tools for policy makers to better target interventions across the whole system to reduce overweight and obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12650-x.

Effects of aging, high-fat diet, and testosterone treatment on neural and metabolic outcomes in male brown Norway rats

Risk for Alzheimer's disease (AD) is affected by multiple factors, including aging, obesity, and low testosterone. We previously showed that obesity and low testosterone independently and interactively exacerbate AD-related outcomes in young adult rodents. The goals of the present study are two-fold: to examine whether the effects of an obesogenic diet differ with increasing age and to determine if testosterone treatment in middle-aged and aged animals mitigates negative effects of the diet. Male brown Norway rats were maintained on control or high-fat diets for 12 weeks beginning in young adulthood, middle age, or advanced age. Separate cohorts of middle-aged and aged animals were treated with testosterone during dietary manipulations. Endpoints included metabolic indices, inflammation, cognitive performance, and neural health outcomes. Aging was associated with poorer outcomes that were generally exacerbated by high-fat diet, especially at middle age. Testosterone treatment was largely without benefit, exerting only subtle effects on a select number of measures. Understanding how the deleterious effects of obesity are affected by advancing age and the ability of protective strategies such as testosterone to reduce these effects may provide significant insight into both the development and prevention of age-related cognitive decline and AD.

Expression of genes involved in carbohydrate-lipid metabolism in muscle and fat tissues in the initial stage of adult-age obesity in fed and fasted mice

C57Bl mice exhibit impaired glucose metabolism by the late adult age under standard living conditions. The aim of this study was to evaluate white adipose tissue (WAT), brown adipose tissue (BAT), and skeletal muscle expression of genes involved in carbohydrate‐lipid metabolism at postpubertal stages preceding the late adult age in C57Bl mice. Muscle mRNA levels of uncoupling protein 3 (Ucp3) and carnitine palmitoyltransferase 1 (Cpt1) (indicators of FFA oxidation), WAT mRNA levels of hormone‐sensitive lipase (Lipe) and lipoprotein lipase (Lpl) (indicators of lipolysis and lipogenesis), muscle and WAT mRNA levels of the type 4 glucose transporter Slc2a4 (indicators of insulin‐dependent glucose uptake), and BAT mRNA levels of uncoupling protein 1 (Ucp1) (indicator of thermogenesis) were measured in fed and 16 h‐fasted mice in three age groups: 10‐week‐old (young), 15‐week‐old (early adult), and 30‐week‐old (late adult). Weight gain from young to early adult age was not accompanied by changes in WAT and BAT indexes and biochemical blood parameters. Weight gain from early to late adult age was accompanied by increased WAT and BAT indexes and decreased glucose tolerance. Muscle Ucp3 and Cpt1 mRNA levels and WAT Lipe and Slc2a4 mRNA levels increased from young to early adult age and then sharply decreased by the late adult age. Moreover, BAT Ucp1 mRNA level decreased in the late adult age. Fasting failed to increase muscle Cpt1 mRNA levels in late adult mice. These transcriptional changes could contribute to impaired glucose metabolism and the onset of obesity in late adult mice during normal development.

Greater body mass index is associated with poorer cognitive functioning in male heart failure patients

BACKGROUND

Heart failure (HF) and obesity are associated with cognitive impairment. However, few studies have investigated the relationship between adiposity and cognitive functioning in HF for each sex, despite observed sex differences in HF prognosis. We tested the hypothesis that greater body mass index (BMI) would be associated with poorer cognitive functioning, especially in men, in sex-stratified analyses.

METHODS AND RESULTS

Participants were 231 HF patients (34% female, 24% nonwhite, average age 68.7 ± 7.3 years). Height and weight were used to compute BMI. A neuropsychology battery tested global cognitive function, memory, attention, and executive function. Composites were created using averages of age-adjusted scaled scores. Regressions adjusting for demographic and medical factors were conducted. The sample was predominantly overweight/obese (76.2%). For men, greater BMI predicted poorer attention (ΔR(2) = 0.03; β = -0.18; P = .01) and executive function (ΔR(2) = 0.02; β = -0.13; P = .04); these effects were largely driven by men with severe obesity (BMI ≥40 kg/m(2)). BMI did not predict memory (P = .69) or global cognitive functioning (P = .08). In women, greater BMI was not associated with any cognitive variable (all P ≥ .09).

DISCUSSION

Higher BMI was associated with poorer attention and executive function in male HF patients, especially those with severe obesity. These patients may therefore have more difficulties with the HF treatment regimen and may have poorer outcomes.

Metabolic mystery: aging, obesity, diabetes, and the ventromedial hypothalamus

We propose that energy balance, glucose homeostasis, and aging are all regulated largely by the same nutrient-sensing neurons in the ventromedial hypothalamus (VMH). Although the central role of these neurons in regulating energy balance is clear, their role in regulating glucose homeostasis has only recently become more clear. This latter function may be most relevant to aging and lifespan by controlling the rate of glucose metabolism. Specifically, glucose-sensing neurons in VMH promote peripheral glucose metabolism, and dietary restriction, by reducing glucose metabolism in these neurons, reduces glucose metabolism of the rest of the body, thereby increasing lifespan. Here we discuss recent studies demonstrating the key role of hypothalamic neurons in driving aging and age-related diseases.

AgRP innervation onto POMC neurons increases with age and is accelerated with chronic high-fat feeding in male mice

In many mammals, body weight increases continuously throughout adulthood until late middle age. The hormone leptin is necessary for maintaining body weight, in that high levels of leptin promote negative energy balance. As animals age, however, their increase in body weight is accompanied by a steady rise in circulating leptin levels, indicating the progressive development of counterregulatory mechanisms to antagonize leptin's anorexigenic effects. Hypothalamic neurons coexpressing agouti-related peptide (AgRP) and neuropeptide Y are direct leptin targets. These neurons promote positive energy balance, and they inhibit anorexigenic proopiomelanocortin (POMC) neurons via direct neuropeptide action and release of γ-aminobutyric acid. We show here that AgRP and neuropeptide Y innvervation onto POMC neurons increases dramatically with age in male mice. This is associated with progressive increase of inhibitory postsynaptic currents and decrease of POMC firing rate with age. Neuronal activity is significantly attenuated in POMC neurons that receive a high density of AgRP puncta. These high-density AgRP inputs correlate with leptin levels in normal mice and are nearly absent in mice lacking leptin. The progression of increased AgRP innervation onto POMC somas is accelerated in hyperleptinemic, diet-induced obese mice. Together our study suggests that modulation of hypothalamic AgRP innervation constitutes one mechanism to counter the effects of the age-associated rise in leptin levels, thus sustaining body weight and fat mass at an elevated level in adulthood.

Hypothalamic Fkbp51 is induced by fasting, and elevated hypothalamic expression promotes obese phenotypes

To discover hypothalamic genes that might play a role in regulating energy balance, we carried out a microarray screen for genes induced by a 48-h fast in male C57Bl/6J mouse hypothalamus. One such gene was Fkbp51 (FK506 binding protein 5; Locus NP_034350). The product of this gene is of interest because it blocks glucocorticoid action, suggesting that fasting-induced elevation of this gene in the hypothalamus may reduce glucocorticoid negative feedback, leading to elevated glucocorticoid levels, thus promoting obese phenotypes. Subsequent analysis demonstrated that a 48-h fast induces Fkbp51 in ventromedial, paraventricular, and arcuate hypothalamic nuclei of mice and rats. To assess if hypothalamic Fkbp51 promotes obesity, the gene was transferred to the hypothalamus via an adeno-associated virus vector. Within 2 wk following Fkbp51 overexpression, mice on a high-fat diet exhibited elevated body weight, without hyperphagia, relative to mice receiving the control mCherry vector. Body weight remained elevated for more than 8 wk and was associated with elevated corticosterone and impaired glucose tolerance. These studies suggest that elevated hypothalamic Fkbp51 promotes obese phenotypes.

High case volumes and surgical fellowships are associated with improved outcomes for bariatric surgery patients: a justification of current credentialing initiatives for practice and training

BACKGROUND

Recent years have seen the establishment of bariatric surgery credentialing processes, center-of-excellence programs, and fellowship training positions. The effects of center-of-excellence status and of the presence of training programs have not previously been examined. The objective of this study was to examine the effects of case volume, center-of-excellence status, and training programs on early outcomes of bariatric surgery.

STUDY DESIGN

Data were obtained from the Nationwide Inpatient Sample from 1998 to 2006. Quantification of patient comorbidities was made using the Charlson Index. Using logistic regression modeling, annual case volumes were analyzed for an association with each institution's center-of-excellence status and training program status. Risk-adjusted outcomes measures were calculated for these hospital-level parameters.

RESULTS

Data from 102,069 bariatric operations were obtained. Adjusting for comorbidities, greater bariatric case volume was associated with improvements in the incidence of total complications (odds ratio [OR] 0.99937 for each single case increase, p = 0.01), in-hospital mortality (OR 0.99717, p < 0.01), and most other complications. Hospitals with a Fellowship Council-affiliated gastrointestinal surgery training program were associated with risk-adjusted improvements in rates of splenectomy (OR 0.2853, p < 0.001) and bacterial pneumonias (OR 0.65898, p = 0.02). Center-of-excellence status, irrespective of the accrediting entity, had minimal independent association with outcomes. A surgical residency program had a varying association with outcomes.

CONCLUSIONS

The hypothesized positive volume-outcomes relationship of bariatric surgery is shown without arbitrarily categorizing hospitals to case volume groups, by analysis of volume as a continuous variable. Institutions with a dedicated fellowship training program have also been shown, in part, to be associated with improved outcomes. The concept of volume-dependent center-of-excellence programs is supported, although no independent association with the credentialing process is noted.

Facing up to uncertain life expectancy: the longevity fan charts

This article uses longevity fan charts to represent the uncertainty in projections of future life expectancy. These fan charts are based on a mortality model calibrated on mortality data for English and Welsh males. The fan charts indicate strong upward sloping trends in future life expectancy. Their widths indicate the extent of uncertainty in these projections, and this uncertainty increases as the forecast horizon lengthens. Allowing for uncertainty in the parameter values of the model adds further to uncertainty in life expectancy projections. The article also illustrates how longevity fan charts can be used to stress-test longevity outcomes.

Laparoscopic sleeve gastrectomy: a retrospective review of 1- and 2-year results

INTRODUCTION

Recently, laparoscopic sleeve gastrectomy (LSG) has been added as a surgical treatment for obesity. We report our 1- and 2-year results with LSG.

METHODS

From September 2005, we have performed 247 LSGs. We retrospectively reviewed our 1- and 2-year data to assess weight loss, body mass index (BMI), percentage excess weight loss (%EWL), length of stay (LOS), complications, and resolution of diabetes.

RESULTS

A total of 40 patients were eligible for follow-up at 2 years, and 157 patients were eligible for follow-up at 1 year. Data was available on 33/40 patients for 2 years and 131/157 patients for 1 year. Initial mean age, mean weight, and mean BMI for 1-year data were 43.2 years, 270.8 lb, and 44.3 kg/m(2), respectively. Initial mean age, mean weight, and mean BMI for 2-year data were 41.4 years, 273.3 lb, and 45.1 kg/m(2), respectively. Mean weight loss, BMI, and %EWL, for patients at 1 year and 2 years were 89.3 lb, 29.6 kg/m(2), and 78% and 87.5 lb, 30.0 kg/m(2), and 75%, respectively. There was no significant difference between use of 46-Fr, 40-Fr, and 36-Fr bougie with respect to weight loss, BMI or %EWL. Likewise, there was no difference seen between use of 7-cm versus 4-cm antral pouch. Mean LOS for both groups was 1.1 days. A total of 12 complications occurred, including one (0.6%) death and two (1.3%) leaks. A total of 39 patients were diabetic, of whom 32 (82%) were cured of diabetes and the remaining 7 patients had their medications decreased.

CONCLUSION

Our results show that LSG is a safe and effective weight-loss procedure with results similar to those of gastric bypass. Additional long-term studies are still needed to accurately compare laparoscopic sleeve gastrectomy with gastric bypass and/or gastric banding.

Clinical application of laparoscopic bariatric surgery: an evidence-based review

BACKGROUND

Approximately one-third of U.S. adults are obese. Current evidence suggests that surgical therapies offer the morbidly obese the best hope for substantial and sustainable weight loss, with a resultant reduction in morbidity and mortality. Minimally invasive methods have altered the demand for bariatric procedures. However, no evidence-based clinical reviews yet exist to guide patients and surgeons in selecting the bariatric operation most applicable to a given situation.

METHODS

This evidenced-based review is presented in conjunction with a clinical practice guideline developed by the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES). References were reviewed by the authors and graded as to the level of evidence. Recommendations were developed and qualified by the level of supporting evidence available at the time of the associated SAGES guideline publication. The guideline also was reviewed and co-endorsed by the American Society for Metabolic and Bariatric Surgery.

RESULTS

Bariatric surgery is the most effective treatment for severe obesity, producing durable weight loss, improvement of comorbid conditions, and longer life. Patient selection algorithms should favor individual risk-benefit considerations over traditional anthropometric and demographic limits. Bariatric care should be delivered within credentialed multidisciplinary systems. Roux-en-Y gastric bypass (RGB), adjustable gastric banding (AGB), and biliopancreatic diversion with duodenal switch (BPD + DS) are validated procedures that may be performed laparoscopically. Laparoscopic sleeve gastrectomy (LSG) also is a promising procedure. Comparative data find that procedures with more dramatic clinical benefits carry greater risks, and those offering greater safety and flexibility are associated with less reliable efficacy.

CONCLUSIONS

Laparoscopic RGB, AGB, BPD + DS, and primary LSG have been proved effective. Currently, the choice of operation should be driven by patient and surgeon preferences, as well as by considerations regarding the relative importance placed on discrete outcomes.

Relationship of body mass index to early complications in knee replacement surgery

BACKGROUND

The purpose of this study was to evaluate the relationship between body mass index and early complications following knee replacement.

METHODS

Five hundred and twenty-seven patients who underwent primary knee replacement were recruited. All these patients were subjected to a pre-operative assessment and follow-up at 6 weeks and 1 year following surgery. Any complication occurring during this period was recorded. Complications were grouped into systemic and local, minor and major.

RESULTS

12.1% (N = 64) patients had an early complication following knee replacement surgery; 9.2% (N = 48) patients had a major complication. Overall BMI did not seem to influence significantly the rate of complication with a P-value of 0.338. A stronger correlation was found between the surgeon and presence of complication with a P-value of 0.004.

CONCLUSIONS

BMI has a weak correlation to early complications following joint replacement surgery. The operating surgeon seems to have a stronger correlation to early complications as compared with BMI.

Increased hypothalamic protein tyrosine phosphatase 1B contributes to leptin resistance with age

Animals at advanced ages exhibit a reduction in central leptin sensitivity. However, changes in growth, metabolism, and obesity risk occur much earlier in life, particularly during the transition from youth to middle age. To determine when initial decreases in central leptin sensitivity occur, leptin-dependent suppression of food intake was tested in 8-, 12-, and 20-wk-old male, chow-fed Sprague Dawley rats. Intracerebroventricular leptin injection (3 microg) suppressed 24-h food intake in 8- and 12-wk-old rats (P < 0.05) but not 20-wk-old rats. To identify potential cellular mediators of this resistance, we focused on protein tyrosine phosphatase 1B (PTP1B), a recently described inhibitor of leptin signaling. PTP1B protein levels, as determined by Western blot, were significantly higher in mediobasal hypothalamic punches collected from 20-wk-old rats, compared with 8-wk-old rats (P < 0.05). When 20-wk-old rats were fasted for 24 h, levels of hypothalamic PTP1B decreased (P < 0.05), coincident with a restoration of leptin sensitivity. To directly test whether inhibition of PTP1B restores leptin sensitivity, 20-wk-old chow-fed rats were pretreated with a pharmacological PTP1B inhibitor 1 h before leptin, and 24-h food intake was recorded. As expected, leptin alone produced a small but nonsignificant reduction in food intake. However, pretreatment with the PTP1B inhibitor resulted in a marked improvement in leptin-dependent suppression of food intake (P < 0.05). These data are consistent with the hypothesis that increases in PTP1B contribute to hypothalamic leptin resistance as rats transition into middle age.

Relationship of body mass index to early complications in hip replacement surgery : study performed at Hinchingbrooke Hospital, Orthopaedic Directorate, Huntingdon, Cambridgeshire

The purpose of this study was to evaluate the relationship between body mass index and early complications following total hip replacements. Five hundred and fifty patients who underwent primary total hip replacement were recruited. All these patients were subjected to a pre-operative assessment and follow-up at 6 weeks and 1 year following surgery. Any complications occurring during this period were recorded. Complications were grouped into systemic and local, both subdivided into minor and major depending on the risk involved. Fifty-six patients (10.2%) had an early complication following hip replacement surgery. Forty-four patients (8%) had a major local complication. Overall, there did seem to be a weak correlation between BMI and the rate of complications, with a p value of 0.104. A correlation was also found between the surgeon and presence of complications with a p value of 0.736. There is a weak correlation between BMI and early complications following hip replacement surgery, and there also seems to be a correlation between the operating surgeon and early complications, but this is not statistically significant.

Effects of hypothalamic neurodegeneration on energy balance

Normal aging in humans and rodents is accompanied by a progressive increase in adiposity. To investigate the role of hypothalamic neuronal circuits in this process, we used a Cre-lox strategy to create mice with specific and progressive degeneration of hypothalamic neurons that express agouti-related protein (Agrp) or proopiomelanocortin (Pomc), neuropeptides that promote positive or negative energy balance, respectively, through their opposing effects on melanocortin receptor signaling. In previous studies, Pomc mutant mice became obese, but Agrp mutant mice were surprisingly normal, suggesting potential compensation by neuronal circuits or genetic redundancy. Here we find that Pomc-ablation mice develop obesity similar to that described for Pomc knockout mice, but also exhibit defects in compensatory hyperphagia similar to what occurs during normal aging. Agrp-ablation female mice exhibit reduced adiposity with normal compensatory hyperphagia, while animals ablated for both Pomc and Agrp neurons exhibit an additive interaction phenotype. These findings provide new insight into the roles of hypothalamic neurons in energy balance regulation, and provide a model for understanding defects in human energy balance associated with neurodegeneration and aging.

Mice are genetically engineered for the progressive degeneration of hypothalamic neurons containing the neuropeptides Pomc and Agrp. Their phenotypes suggest a model for energy balance changes associated with aging.

Misdirection on the road to Shangri-La

Will life expectancy in the United States rise or fall in this century? The implications of either scenario are far reaching. We contend that the rise of childhood obesity in the United States in the past three decades has been so dramatic that it will soon lead to higher than expected death rates at middle ages and a possible decline in life expectancy by midcentury. The most detrimental health and longevity effects will not be seen for decades--a phenomenon that cannot be detected by current methods used to forecast life expectancy or estimate the number of deaths currently attributable to obesity. This scenario contrasts sharply with the views of mathematical demographers who generate forecasts by relying on the assumption that the U.S. pattern of longevity will follow that of other longer lived nations and on the extrapolation of historical trends in life expectancy into the future.