Analysis of the adiponectin paradox in healthy older people

Association of biomarkers and Barthel Index with occurrence of age-related adverse health outcomes in individuals with diabetes

AIMS/INTRODUCTION

The clinical significance of age-related biomarkers in patients with diabetes has not been fully elucidated. In this study, we aimed to establish models to predict the progression of aging in patients with diabetes using biomarkers.

MATERIALS AND METHODS

This single-center, retrospective cohort study included 115 Japanese patients with diabetes aged ≥60 years. Age-related adverse health outcomes were defined as emergency hospitalization, any increase in the level of nursing care certification, admission to a nursing home or death. The associations of age-related biomarker levels (adiponectin, growth differentiation factor 15 [GDF15], C-X-C motif chemokine ligand 9 and apelin) and clinical indicators with age-related adverse health outcomes were evaluated. Factors that predominantly influenced the occurrence of age-related adverse health outcomes were explored using the Cox proportional hazards model.

RESULTS

The mean age of the 115 participants was 73 years, 50.6% were men, the mean body mass index and hemoglobin A1c level were 25.3 kg/m2 and 9.79%, respectively. There were 26 age-related adverse health outcomes during the study period (median 1.93, range 0-4.65 years). In a model combining clinical indicators and biomarkers, including the Barthel Index, GDF15 and adiponectin, the occurrence of age-related adverse health outcomes was found to be significantly associated with GDF15 and Barthel Index. The group with both GDF15 and adiponectin levels higher than the median proved to be significantly higher than the group with both lower.

CONCLUSIONS

The measurement of GDF15 and adiponectin levels and the Barthel Index might be useful for predicting age-related adverse health outcomes in patients with diabetes.

Reevaluating Adiponectin's impact on obesity hypertension: a Chinese case-control study

BACKGROUND

Obesity and hypertension are major risk factors for cardiovascular diseases that affect millions of people worldwide. Both conditions are associated with chronic low-grade inflammation, which is mediated by adipokines such as adiponectin. Adiponectin is the most abundant adipokine that has a beneficial impact on metabolic and vascular biology, while high serum concentrations are associated with some syndromes. This "adiponectin paradox" still needs to be clarified in obesity-associated hypertension. The aim of this study was to investigate how adiponectin affects blood pressure, inflammation, and metabolic function in obesity hypertension using a Chinese adult case-control study.

METHODS

A case-control study that had finished recruiting 153 subjects divided as four characteristic groups. Adiponectin serum levels were tested by ELISA in these subjects among these four characteristic Chinese adult physical examination groups. Waist circumference (WC), body mass index (BMI), systolic blood pressure (SB), diastolic blood pressure (DB), and other clinical laboratory data were collected. Analyzation of correlations between the research index and differences between groups was done by SPSS.

RESULTS

Serum adiponectin levels in the| normal healthy group (NH group) were significantly higher than those in the newly diagnosed untreated just-obesity group (JO group), and negatively correlated with the visceral adiposity index. With multiple linear egression analysis, it was found that, for serum adiponectin, gender, serum albumin (ALB), alanine aminotransferase (ALT) and high-density lipoprotein cholesterol (HDLC) were the significant independent correlates, and for SB, age and HDLC were the significant independent correlates, and for DB, alkaline phosphatase (ALP) was the significant independent correlate. The other variables did not reach significance in the model.

CONCLUSIONS

Our study reveals that adiponectin's role in obesity-hypertension is multifaceted and is influenced by the systemic metabolic homeostasis signaling axis. In obesity-related hypertension, compensatory effects, adiponectin resistance, and reduced adiponectin clearance from impaired kidneys and liver all contribute to the "adiponectin paradox".

Limitations in metabolic plasticity after traumatic injury are only moderately exacerbated by physical activity restriction

Following traumatic musculoskeletal injuries, prolonged bedrest and loss of physical activity may limit muscle plasticity and drive metabolic dysfunction. One specific injury, volumetric muscle loss (VML), results in frank loss of muscle and is characterized by whole-body and cellular metabolic dysfunction. However, how VML and restricted physical activity limit plasticity of the whole-body, cellular, and metabolomic environment of the remaining uninjured muscle remains unclear. Adult mice were randomized to posterior hindlimb compartment VML or were age-matched injury naïve controls, then randomized to standard or restricted activity cages for 8-wks. Activity restriction in naïve mice resulted in ~5% greater respiratory exchange ratio (RER); combined with VML, carbohydrate oxidation was ~23% greater than VML alone, but lipid oxidation was largely unchanged. Activity restriction combined with VML increased whole-body carbohydrate usage. Together there was a greater pACC:ACC ratio in the muscle remaining, which may contribute to decreased fatty acid synthesis. Further, β-HAD activity normalized to mitochondrial content was decreased following VML, suggesting a diminished capacity to oxidize fatty acids. The muscle metabolome was not altered by the restriction of physical activity. The combination of VML and activity restriction resulted in similar (~91%) up- and down-regulated metabolites and/or ratios, suggesting that VML injury alone is regulating changes in the metabolome. Data supports possible VML-induced alterations in fatty acid metabolism are exacerbated by activity restriction. Collectively, this work adds to the sequala of VML injury, exhausting the ability of the muscle remaining to oxidize fatty acids resulting in a possible accumulation of triglycerides.

Preliminary Report on the Influence of Acute Inflammation on Adiponectin Levels in Older Inpatients with Different Nutritional Status

Inflammation can be triggered by a variety of factors, including pathogens, damaged cells, and toxic compounds. It is a biological response of the immune system, which can be successfully assessed in clinical practice using some molecular substances. Because adiponectin, a hormone released by adipose tissue, influences the development of inflammation, its evaluation as a potential measure of inflammation in clinical practice is justified. In the present contribution, statistical comparison of adiponectin concentration and selected molecular substances recognized in clinical practice as measures of inflammation were utilized to demonstrate whether adipose tissue hormones, as exemplified by adiponectin, have the potential to act as a measure of rapidly changing inflammation when monitoring older hospitalized patients in the course of bacterial infection. The study showed no statistically significant differences in adiponectin levels depending on the rapidly changing inflammatory response in its early stage. Interestingly, the concentration of adiponectin is statistically significantly higher in malnourished patients than in people with normal nutritional levels, assessed based on the MNA. According to the results obtained, adiponectin is not an effective measure of acute inflammation in clinical practice. However, it may serve as a biomarker of malnutrition in senile individuals.

The association of serum adiponectin level with activities of daily living in hospitalized elderly patients with heart failure

BACKGROUND

Several studies have reported a relationship between elevated serum adiponectin levels and poor outcomes in patients with heart failure (HF). However, data on the activities of daily living (ADL) in elderly patients with HF are limited.

METHODS

We evaluated 218 hospitalized elderly (≥65 years) patients with HF who underwent a comprehensive cardiac rehabilitation (CR) program during hospitalization. Serum adiponectin levels were measured before discharge. The Barthel index (BI) score was evaluated at discharge. Low ADL was defined as a BI score < 85.

RESULTS

Serum adiponectin levels were significantly associated with low ADL [p = 0.03; odds ratio (OR), 1.024, per 1.0 μg/mL increase]. In logistic or regression analyses adjusted for age, sex, body mass index, and estimated glomerular filtration rate, high adiponectin levels (≥16.2 μg/mL) were significantly associated with low ADL (p = 0.04; OR, 2.53), malnutrition (p < 0.01; OR, 2.88), and 6-min walk distance (p = 0.04; β = -17.5). In the multivariate analysis adjusted for conventional risk factors of low ADL, high adiponectin levels were also significantly associated with low ADL (p = 0.03; OR, 2.68). In the stepwise forward selection procedure, a high adiponectin level was an independent determinant of low ADL (p = 0.02; R2 = 0.0262). Both net reclassification improvement (0.53; p < 0.01) and integrated discrimination improvement (0.02; p = 0.01) improved significantly after the addition of high adiponectin level to conventional risk factors. In the regression analysis adjusted for age and sex, serum adiponectin levels were significantly (p < 0.0025) negatively associated with abdominal visceral and subcutaneous adipose tissue areas, body weight, body mass index, and serum triglyceride levels.

CONCLUSIONS

High serum adiponectin levels were not only significantly associated with an increased risk of low ADL, but also with an increased risk of malnutrition and low physical activity in elderly patients with HF after the in-hospital CR program.

Sarcopenia, a condition shared by various diseases: can we alleviate or delay the progression?

Sarcopenia is a severe condition common to various chronic diseases and it is reckoned as a major health problem. It encompasses many different molecular mechanisms that have been for a while discovered but not definitely clarified. Although sarcopenia is a disability status that leads to serious health consequences, the scarcity of suitable animal models has curtailed research addressing this disorder. Another limitation in the field of clinical investigation of sarcopenic patients is the lack of a generally accepted definition coupled with the difficulty of adopting common diagnostic criteria. In fact, both do not permit to clarify the exact prevalence rate and consequently limit physicians to establish any kind of therapeutical approach or, when possible, to adopt preventive measures. Unfortunately, there is no standardized cure, apart from doing more physical activity and embracing a balanced diet, but newly discovered substances start being considered. In this review, authors try to give an overview addressing principal pathways of sarcopenia and offer critical features of various possible interventions.

Determinants of bone mass in older adults with normal- and overweight derived from the crosstalk with muscle and adipose tissue

Lower bone mass in older adults may be mediated by the endocrine crosstalk between muscle, adipose tissue and bone. In 150 community-dwelling adults (59-86 years, BMI 17-37 kg/m²; 58.7% female), skeletal muscle mass index, adipose tissue and fat mass index (FMI) were determined. Levels of myokines, adipokines, osteokines, inflammation markers and insulin were measured as potential determinants of bone mineral content (BMC) and density (BMD). FMI was negatively associated with BMC and BMD after adjustment for mechanical loading effects of body weight (r-values between -0.37 and -0.71, all p < 0.05). Higher FMI was associated with higher leptin levels in both sexes, with higher hsCRP in women and with lower adiponectin levels in men. In addition to weight and FMI, sclerostin, osteocalcin, leptin × sex and adiponectin were independent predictors of BMC in a stepwise multiple regression analysis. Muscle mass, but not myokines, showed positive correlations with bone parameters that were weakened after adjusting for body weight (r-values between 0.27 and 0.58, all p < 0.01). Whereas the anabolic effect of muscle mass on bone in older adults may be partly explained by mechanical loading, the adverse effect of obesity on bone is possibly mediated by low-grade inflammation, higher leptin and lower adiponectin levels.