Obesity is associated with insulin resistance but not skeletal muscle dysfunction or all-cause mortality

Association between calf circumference and cardiac metabolic risk factors in middle-aged and elderly women

Aims

To assess the correlation between calf circumference and cardiac metabolic risk factors such as hypertension, abnormal blood glucose and dyslipidaemia among middle-aged and elderly women.

Methods

The cross-sectional study population consisted of 476 female participants aged 40-80 years, including 304 perimenopausal and 172 postmenopausal women. Calf circumference, body mass index (BMI), blood pressure, blood glucose and blood lipids were measured. Logistic regression analysis was used to evaluate the study aims.

Results

Calf circumference was lower in postmenopausal than perimenopausal women, and postmenopausal women had the highest rates of hypertension, abnormal blood glucose and abnormal blood lipids. Pearson correlation coefficients showed that calf circumference was positively correlated with triglycerides (TGs), BMI, fasting plasma glucose (FPG),2-h plasma glucose, glycated haemoglobin (HbA1C), systolic blood pressure and diastolic blood pressure; and negatively correlated with high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC). The group with the lowest quantile of calf circumference had higher rates of hypertension (odds ratio (OR)2.14,95% confidence interval (CI)1.67-2.74),dysglycaemia (OR1.40,95%CI1.03-1.90) and dyslipidaemia (OR2.14,95%CI 1.86-2.46).

Conclusion

In perimenopausal women, measurements of calf circumference can be used to predict the presence of cardiac metabolic risk factors, which can be detected by observing blood pressure, blood glucose, and blood lipids.

Effect of 2-year caloric restriction on organ and tissue size in nonobese 21- to 50-year-old adults in a randomized clinical trial: the CALERIE study

BACKGROUND

Sustained calorie restriction (CR) promises to extend the lifespan. The effect of CR on changes in body mass across tissues and organs is unclear.

OBJECTIVES

We used whole-body MRI to evaluate the effect of 2 y of CR on changes in body composition.

METHODS

In an ancillary study of the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) trial, 43 healthy adults [25-50 y; BMI (kg/m2): 22-28] randomly assigned to 25% CR (n = 28) or ad libitum (AL) eating (n = 15) underwent whole-body MRI at baseline and month 24 to measure adipose tissue in subcutaneous, visceral, and intermuscular depots (SAT, VAT, and IMAT, respectively); skeletal muscle; and organs including brain, liver, spleen, and kidneys but not heart.

RESULTS

The CR group lost more adipose tissue and lean tissue than controls (P < 0.05). In the CR group, at baseline, total tissue volume comprised 32.1%, 1.9%, and 1.0% of SAT, VAT, and IMAT, respectively. The loss of total tissue volume over 24 mo comprised 68.4%, 7.4%, and 2.2% of SAT, VAT, and IMAT, respectively, demonstrating preferential loss of fat vs. lean tissue. Although there is more muscle loss in CR than AL (P < 0.05), the loss of muscle over 24 mo in the CR group comprised only 17.2% of the loss of total tissue volume. Changes in organ volumes were not different between CR and AL. The degree of CR (% decrease in energy intake vs. baseline) significantly (P < 0.05) affected changes in VAT, IMAT, muscle, and liver volume (standardized regression coefficient ± standard error of estimates: 0.43 ± 0.15 L, 0.40 ± 0.19 L, 0.55 ± 0.17 L, and 0.45 ± 0.18 L, respectively).

CONCLUSIONS

Twenty-four months of CR (intended, 25%; actual, 13.7%) in young individuals without obesity had effects on body composition, including a preferential loss of adipose tissue, especially VAT, over the loss of muscle and organ tissue. This trial was registered at www.clinicaltrials.gov as NCT02695511.

Calf circumference and risk of cardiovascular disease

AIM

Calf circumference (CC) is an anthropometric parameter that is easily obtained. Increasingly, research has shown that CC related to cardiovascular events. We aimed to determine the correlation between CC and Framingham risk score (FRS) for the 10-year cardiovascular disease risk assessment in Taiwanese elderly aged ≥65 years.

METHODS

We included 540 men and 683 women aged ≥65 years. All participants and data were collected from geriatric physical screenings in Tri-Service General Hospital in Taiwan during 2017. The correlation between CC and FRS-coronary heart disease (CHD) were calculated. We used multivariate regression models to investigate the correlation between CC and FRS-CHD. Covariate adjustments were investigated by performing an extended model.

RESULTS

A significantly negative association was observed between FRS-CHD and CC in both genders in both models (all P < 0.05). Male and female participants were divided into quartiles at the CC level (Q1-Q4) and we compared their baseline characteristics separately. We further explored the association between CC divided in quartiles and the FRS-CHD, which exhibited a significant negative correlation comparing the largest quartiles with the first quartile in a fully adjusted model in both genders (P < 0.05). In addition, the higher quartiles of CC seemed to have a lower FRS-CHD with statistical significance (P for trend <0.05).

DISCUSSION

CC had a strongly negative correlation with FRS-CHD in both genders. In the future, CC might be an applicable tool in geriatric research in Taiwan for the early detection of developing cardiovascular events. Geriatr Gerontol Int 2020; 20: 1133-1137.

Calorie Restriction and Aging in Humans

Calorie restriction (CR), the reduction of dietary intake below energy requirements while maintaining optimal nutrition, is the only known nutritional intervention with the potential to attenuate aging. Evidence from observational, preclinical, and clinical trials suggests the ability to increase life span by 1-5 years with an improvement in health span and quality of life. CR moderates intrinsic processes of aging through cellular and metabolic adaptations and reducing risk for the development of many cardiometabolic diseases. Yet, implementation of CR may require unique considerations for the elderly and other specific populations. The objectives of this review are to summarize the evidence for CR to modify primary and secondary aging; present caveats for implementation in special populations; describe newer, alternative approaches that have comparative effectiveness and fewer deleterious effects; and provide thoughts on the future of this important field of study.

Does the Additional Component of Calf Circumference Refine Metabolic Syndrome in Correlating With Cardiovascular Risk?

CONTEXT

Calf circumference (CC) was a useful anthropometric tool, but there was limited study on the effect of CC on metabolic syndrome (MetS) for cardiovascular risk.

OBJECTIVE

The objective of our study was to determine whether adding CC as a component of MetS refined correlating MetS with cardiovascular, all-cause, and cancer mortality risks.

DESIGN, SETTING, PATIENTS, AND INTERVENTIONS

From the National Health and Nutrition Examination Survey data set for 1999 through 2002, we analyzed four types of MetS: (1) increased waist circumference and two or more of four MetS components (WaistMetS); (2) decreased CC and two or more of four MetS components (CalfMetS); (3) increased waist-to-calf ratio and two or more of four MetS components (WCRMetS); and (4) decreased CC and three or more of five MetS components (CC+MetS).

PRIMARY OUTCOME MEASURE

The cause-specific hazard ratios were measured as categorized by the four types of MetS.

RESULTS

For cardiovascular mortality, the adjusted hazard ratios for WaistMetS, CalfMetS, WCRMetS, and CC+MetS were 1.867, 1.871, 1.949, and 2.306, respectively (all P < 0.001). Notably, CalfMetS showed the strongest positive correlation with serum C-reactive protein levels, and WCRMetS had the strongest positive relationship with homeostasis model assessment of insulin resistance.

CONCLUSIONS

Adding CC to the components of MetS correlated with higher cardiovascular and all-cause mortality risk than the traditional definition of MetS.

Age-related changes in central effects of corticotropin-releasing factor (CRF) suggest a role for this mediator in aging anorexia and cachexia

Hypothalamic corticotropin-releasing factor (CRF) lays downstream to catabolic melanocortins and at least partly mediates their catabolic effects. Age-related changes in the melanocortin system (weak responsiveness in middle-aged and a strong one in old rats) have been shown to contribute to middle-aged obesity and later to aging anorexia and cachexia of old age groups. We hypothesized that catabolic (anorexigenic and hypermetabolic) CRF effects vary with aging similarly to those of melanocortins. Thus, we aimed to test whether age-related variations of CRF effects may also contribute to middle-aged obesity and aging anorexia leading to weight loss of old age groups. Food intake, body weight, core temperature, heart rate, and activity were recorded in male Wistar rats of young, middle-aged, aging, and old age groups (from 3 to 24 months) during a 7-day intracerebroventricular CRF infusion (0.2 μg/μl/h) in a biotelemetric system. In addition, CRF gene expression was also assessed by quantitative RT-PCR in the paraventricular nucleus (PVN) of intact animals of the same age groups. The infusion suppressed body weight in the young, aging, and old rats, but not in middle-aged animals. Weak anorexigenic and hypermetabolic effects were detected in the young, whereas strong anorexia (without hypermetabolism) developed in the oldest age groups in which post mortem analysis showed also a reduction of retroperitoneal fat mass. CRF gene expression in the PVN increased with aging. Our results support the potential contribution of age-related changes in CRF effects to aging anorexia and cachexia. The role of the peptide in middle-aged obesity cannot be confirmed.

Beyond Diabetes: Does Obesity-Induced Oxidative Stress Drive the Aging Process?

Despite numerous correlative data, a causative role for oxidative stress in mammalian longevity has remained elusive. However, there is strong evidence that increased oxidative stress is associated with exacerbation of many diseases and pathologies that are also strongly related to advanced age. Obesity, or increased fat accumulation, is one of the most common chronic conditions worldwide and is associated with not only metabolic dysfunction but also increased levels of oxidative stress in vivo. Moreover, obesity is also associated with significantly increased risks of cardiovascular disease, neurological decline and cancer among many other diseases as well as a significantly increased risk of mortality. In this review, we investigate the possible interpretation that the increased incidence of these diseases in obesity may be due to chronic oxidative stress mediating segmental acceleration of the aging process. Understanding how obesity can alter cellular physiology beyond that directly related to metabolic function could open new therapeutic areas of approach to extend the period of healthy aging among people of all body composition.

Molecular studies of exercise, skeletal muscle, and ageing

The purpose of an F1000 review is to reflect on the bigger picture, exploring controversies and new concepts as well as providing opinion as to what is limiting progress in a particular field. We reviewed about 200 titles published in 2015 that included reference to 'skeletal muscle, exercise, and ageing' with the aim of identifying key articles that help progress our understanding or research capacity while identifying methodological issues which represent, in our opinion, major barriers to progress. Loss of neuromuscular function with chronological age impacts on both health and quality of life. We prioritised articles that studied human skeletal muscle within the context of age or exercise and identified new molecular observations that may explain how muscle responds to exercise or age. An important aspect of this short review is perspective: providing a view on the likely 'size effect' of a potential mechanism on physiological capacity or ageing.