Relationship between serum adiponectin levels and disability-free survival among community-dwelling elderly individuals: The Tsurugaya Project

Sarcopenia in knee osteoarthritis: the association with clinical and sonographic findings, physical function, and nutrition

OBJECTIVE

The purposes of this study were to examine to (1) the relation between OA and sarcopenia and to identify the most practical, easily accessible, and inexpensive method for investigating sarcopenia; (2) evaluation of sarcopenia risk factors in patients with OA.

DESIGN

One hundred two patients with clinical and radiological diagnosis of knee osteoarthritis and 33 healthy control subjects were included in the study and all subjects were evaluated for sarcopenia. Dual-X-ray absorptiometry (DEXA) is used to measure body composition parameters and muscle thickness measurements with ultrasonography for diagnosis of sarcopenia.

RESULTS

The mean age of the group with sarcopenia was statistically higher than the other two groups (p < 0.001). The weight, body mass index (BMI), waist circumference, upper-mid-arm circumference, thigh, and leg circumference of osteoarthritis (OA) patients with sarcopenia were statistically lower than those of non-sarcopenic and control group (p < 0.01, p < 0.001). Body composition parameter results showed that sarcopenic patients had statistically lower values as fat mass, lean body mass, and skeletal muscle index (p < 0.001, p = 0.001, p < 0.001, respectively) than those of non-sarcopenic and control group and fat mass index values (p = 0.012) are lower than the non-sarcopenic group. With respect to sarcopenia, the effect of adiponectin and leptin levels were not detected. It was determined that body composition values measured with DEXA, ultrasonographic measures, isokinetic muscle strength assessment, handgrip strength, and gait speed had predictive values for sarcopenia.

CONCLUSIONS

We found that patients with sarcopenic OA were older, weaker, undernourished, and restricted in their level of physical activity in the study. Among the methods of determining sarcopenia, ultrasound becomes prominent with its practical, cheap, and easily accessible features. We think that our results will increase the awareness of the presence of sarcopenia in OA patients.

Elevations in adipocytokines and mortality in rheumatoid arthritis

OBJECTIVES

This study assessed whether circulating levels of adiponectin and leptin are associated with higher mortality in patients with RA.

METHODS

Participants were adults from the Veterans Affairs RA Registry. Adipokines and inflammatory cytokines were measured as part of a multi-analyte panel on banked serum at enrolment. Dates and causes of death were derived from the Corporate Data Warehouse and the National Death Index. Covariates were derived from medical record, biorepository and registry databases. Multivariable Cox proportional hazard models evaluated associations between biomarkers and all-cause and cause-specific mortality.

RESULTS

A total of 2583 participants were included. Higher adiponectin levels were associated with older age, male sex, white race, lower BMI, autoantibody seropositivity, radiographic damage, longer disease duration, prednisone use and osteoporosis. Higher adiponectin concentrations were also associated with higher levels of inflammatory cytokines but not higher disease activity at enrolment. Leptin was primarily associated with greater BMI and comorbidity. The highest quartile of adiponectin (vs lowest quartile) was associated with higher all-cause mortality [hazard ratio (HR): 1.46 (95% CI: 1.11, 1.93), P = 0.009] and higher cardiovascular mortality [HR: 1.85 (95% CI: 1.24, 2.75), P = 0.003], after accounting for covariates. Higher leptin levels were also associated with greater all-cause and cancer mortality.

CONCLUSIONS

Elevations in adipokines are associated with age, BMI, comorbidity and severe disease features in RA and independently predict early death. Associations between adiponectin and inflammatory cytokines support the hypothesis that chronic subclinical inflammation promotes metabolic changes that drive elevations in adipokines and yield adverse health outcomes.

Risk Factors of Long-Term Care Insurance Certification in Japan: A Scoping Review

This study aimed to review evidence on future long-term care associated with pre-existing factors among community-dwelling Japanese older adults. We systematically searched cohort and nested case-control studies published between 2000 and 2019 that assessed long-term care certification using the PubMed, CINAHL, and EMBASE databases. The relationship between long-term care insurance information and risk factors was investigated. The protocol was registered with the Open Science Framework. We extracted 91 studies for synthesis, including 84 prospective cohort studies, 1 retrospective cohort study, and 6 nested case-control studies. Certification for long-term care was classified into two endpoints: onset of functional disability and dementia. There were 72 studies that used long-term care certification as a proxy for functional disability, and 22 used long-term care information to indicate the onset of dementia. Common risk factors related to functional disability were physical function, frailty, and oral condition. Motor function and nutritional status were common risk factors for dementia. We found consistent associations between premorbid risk factors and functional disability and dementia. The accumulation of evidence on the incidence of long-term care and associated factors can aid the development of preventive measures. Future studies should aim to integrate this evidence.

Association of serum adiponectin levels and body mass index with worsening depressive symptoms in elderly individuals: a 10-year longitudinal study

Objectives: Data regarding the association between adiponectin levels and body mass index (BMI) and long-term changes in depressive symptoms are limited and inconsistent. Thus, we investigated whether circulating adiponectin levels and BMI were independently and combinedly correlated to longitudinal changes in depressive symptoms.Methods: This prospective cohort study evaluated 269 elderly Japanese individuals aged ≥70 years who participated in the Tsurugaya Project conducted between 2002 and 2012. A short form of the Geriatric Depression Scale (GDS) was used to assess depressive status. Serum adiponectin levels were measured using an enzyme-linked immunosorbent assay or a latex particle-enhanced turbidimetric immunoassay. BMI was calculated as body weight (kg)/height (m²).Results: Multiple linear regression analysis revealed that baseline serum adiponectin levels were positively associated with changes in GDS scores (β = 0.14, P = 0.035). However, no association was observed after adjusting for BMI (β = 0.09, P = 0.185). Low BMI was associated with increased GDS scores at the 10-year follow-up (β = -0.14, P = 0.033). Participants with a combination of high adiponectin levels and low BMI had a 3.3-fold higher risk of worsening depressive symptoms than those with low adiponectin levels and high BMI (odds ratio: 3.35, 95% confidence interval: 1.60-7.00; P = 0.001).Conclusions: This longitudinal study indicated that high serum adiponectin levels and low BMI were both associated with worsening depressive symptoms among older Japanese individuals. Furthermore, the combination of high adiponectin levels and low BMI was associated with worsening depressive symptoms.

The Adiponectin Paradox in the Elderly: Associations With Body Composition, Physical Functioning, and Mortality

Background

To determine if adiponectin levels are associated with weight loss, low muscle mass, and physical functioning among the elderly and to determine independent associations with incident disability and death.

Methods

Included were 3,044 participants from the Health, Aging and Body Composition Study, who had whole-body dual energy absorptiometry performed to evaluate appendicular lean mass index (ALMI, kg/m2) and fat mass index (FMI, kg/m2), computed tomography measures of thigh muscle density, weight histories, estimates of physical functioning, and adiponectin levels at enrollment. Associations between adiponectin levels and body composition, weight loss, and physical functioning were assessed in multivariable linear regression models. Associations between adiponectin and incident disability and mortality were assessed in mediation analyses, adjusting for other factors.

Results

Greater adiponectin at baseline was independently associated with low FMI Z-score, lower waist circumference, low ALMI Z-score, low muscle density, a history of weight loss, and poor physical functioning (all p < .05). Greater adiponectin levels (per SD) were associated with incident disability [HR: 1.14 (1.08, 1.20), p < .001] and greater mortality [HR: 1.17 (1.10, 1.25), p < .001] in models adjusting for demographic factors, adiposity, and comorbid conditions. The association was completely attenuated and no longer significant (all p > 0.05) when adjusting for body composition, muscle density, weight loss, and physical functioning at baseline.

Conclusions

Greater serum adiponectin levels are associated with historical weight loss, low skeletal muscle mass, low muscle density, and poor physical functioning. High adiponectin is associated with a greater risk of incident disability and death, but not independently of these factors.

Serum adiponectin is associated with body composition and cognitive and psychological status in older adults living in long-term nursing homes

Frailty is a geriatric syndrome characterized by decreasing functional reserves and increasing vulnerability to falls, injuries and declining health, leading to dependence upon caregivers. Frailty is associated not only with physical decline, but also with cognitive and psychological impairments in aging people. Higher serum adiponectin concentration has been linked to better performance on frailty measures but also to worse cognitive status. Nonetheless, several studies have proposed adiponectin as a frailty biomarker. To further delineate the relationship between adiponectin serum levels and frailty-related parameters, we studied a population of 112 long-term nursing home residents (aged 84.9 ± 6.7) and analyzed their serum adiponectin levels in conjunction with frailty-related parameters including body composition, physical fitness, cognitive function, psychological parameters and quality of life. Frailty was assessed following the Fried Frailty Criteria, the Clinical Frailty Scale and the Tilburg Frailty Indicator. In women, higher serum adiponectin levels were associated with lower body weight, body mass index, body fat mass, fat mass/height², lean mass, lean mass/height² and smaller waist circumference and hip circumference (p < 0.05). In men, the association was positive (p < 0.05) between serum adiponectin and percentage of fat mass and negative between serum adiponectin and percentage of lean mass. Interestingly, in men, better cognitive function was inversely related to adiponectin (p < 0.05) while decreased anxiety was linked to a higher concentration of adiponectin in women (p < 0.05). According to the Tilburg Frailty Indicator, frail men had lower levels of adiponectin than those who were not frail (p < 0.05). Variables that predicted adiponectin concentration in multiple regression models were different for women and men. In women, lean mass and anxiety were independent negative predictors of blood adiponectin (β = -0.363, p = 0.002; β = -0.204, p = 0.067, respectively). In men, the Montreal Cognitive Assessment (MOCA) test was the only parameter to remain significant in the regression model (β = -439, p = 0.015). The results of our study show that adiponectin is linked to body composition, cognitive function and anxiety in long-term nursing home residents with differential relationships by sex. Further studies should be conducted to determine whether adiponectin is a valid and reliable frailty biomarker.

Dental Status is Associated With Incident Functional Disability in Community-Dwelling Older Japanese: A Prospective Cohort Study Using Propensity Score Matching

Background

A growing number of epidemiology studies have shown that poor oral health is associated with an increased incidence of functional disability. However, there are few studies in which the confounding bias is adjusted appropriately. In this study, we examined whether dental status is associated with functional disability in elderly Japanese using a 13-year prospective cohort study after elimination of confounding factors with propensity score matching.

Methods

Participants were community-dwelling Japanese aged 70 years or older who lived in the Tsurugaya district of Sendai (n = 838). The number of remaining teeth (over 20 teeth vs 0–19 teeth) was defined as the exposure variable. The outcome was the incidence of functional disability, defined as the first certification of long-term care insurance (LTCI) in Japan. The variables that were used to determine propensity score matching were age, sex, body mass index (BMI), medical history (stroke, hypertension, myocardial infarction, cancer, and diabetes), smoking, alcohol consumption, educational attainment, depression symptoms, cognitive impairment, physical function, social support, and marital status.

Results

As a result of the propensity score matching, 574 participants were selected. Participants with 0–19 teeth were more likely to develop functional disability than those with 20 or more teeth (hazard ratio 1.33; 95% confidence interval, 1.01–1.75).

Conclusions

In this prospective cohort study targeting community-dwelling older adults in Japan, having less than 20 teeth was confirmed to be an independent risk factor for functional disability even after conducting propensity score matching. This study supports previous publications showing that oral health is associated with functional disability.

Dietary Inflammatory Index and Disability-Free Survival in Community-Dwelling Older Adults

Background: Previous studies have reported that a higher dietary inflammatory index (DII^®) score is related to a higher risk of mortality and conditions that result in functional disability, such as cardiovascular disease, dementia, and fractures. Although these findings suggest that higher DII scores would affect disability-free survival, this has never been investigated directly. The present study investigated the association between the DII score and disability-free survival. Methods: We analyzed follow-up data covering a 12-year period for 793 older adults (≥70 years) participating in a Japanese community-based cohort study. DII scores were computed on the basis of dietary intake and assessed using the Brief Self-Administered Diet History Questionnaire. Data on incident functional disability were retrieved from the public Long-Term Care Insurance database. We applied the Cox model for estimating the adjusted hazard ratios (HRs) of the composite outcome (incident functional disability or death) according to DII score tertiles (T1–T3). Results: The proportion of men was 47.3%; mean (SD) age was 75.2 (4.5) years. The 12-year incidence of the composite outcome was 65.5%. A higher DII score was related to a higher risk for the composite outcome: HRs (95% confidence interval) were 1.05 (0.84, 1.32) for T2 and 1.26 (1.01, 1.57) for T3 (p-trend = 0.040) compared to the most anti-inflammatory T1 reference (HR = 1.00). Conclusions: These results suggest that a pro-inflammatory diet might be a modifiable factor affecting disability-free survival in the older population. Additional prospective studies are needed to confirm this relationship.

Associations of Abdominal Muscle Area and Radiodensity with Adiponectin and Leptin: The Multiethnic Study of Atherosclerosis

OBJECTIVE

This study examined the associations of muscle area and radiodensity with adiponectin and leptin.

METHODS

A total of 1,944 participants who enrolled in the Multi-Ethnic Study of Atherosclerosis underwent computed tomography to quantify body composition and measurements of adiponectin, leptin, interleukin-6, C-reactive protein, and resistin.

RESULTS

The mean age and BMI of participants were 64.7 years and 28.1 kg/m2 and 49% were female. With adjustment for age, gender, race/ethnicity, traditional cardiovascular disease risk factors, inflammatory biomarkers, physical activity, and sedentary behavior, a 1-SD increment in total abdominal, stability, and locomotor muscle area was associated with a 19%, 17%, and 12% lower adiponectin level, respectively (P < 0.01 for all) but not leptin (P > 0.05). Muscle radiodensity was more robustly associated with adiponectin and leptin in the multivariable linear regression models. That is, with full adjustment for all covariates, a 1-SD increment in total abdominal, stability, and locomotor muscle radiodensity was associated with a 31%, 31%, and 18% lower adiponectin level (P < 0.01 for all) and a 6.7%, 4.6%, and 8.1% higher leptin level (P < 0.05 for all), respectively.

CONCLUSIONS

The data suggest that increases in muscle area and radiodensity may have positive impacts on chronic inflammation and, in turn, reduce the risk of cardiometabolic disease.

High-molecular-weight adiponectin levels in healthy, community-dwelling, elderly Japanese volunteers: a 5-year prospective observational study

BACKGROUND

Serum adiponectin levels are associated with frailty and cardiovascular diseases. Longitudinal changes in adiponectin levels might enhance our understanding of age-related conditions and diseases.

AIMS

This prospective observational study aimed to: (1) elucidate age-related changes in high-molecular-weight (HMW) adiponectin levels; and (2) identify variables predictive of elevated HMW adiponectin levels and the association with well-known adiponectin single-nucleotide polymorphisms (SNPs) in healthy, elderly Japanese participants.

METHODS

Healthy elderly volunteers (n = 196; 55 men and 141 women; median age 72.0 years; range 69.0-75.0 years) underwent anthropometric and physical function measurements, as well as laboratory tests at baseline and the 5-year follow-up.

RESULTS

HMW adiponectin levels were significantly higher in women than in men (8.4, 5.3-11.9 vs. 5.7, 3.1-9.0 μg/mL; p < 0.001) at baseline and decreased significantly at follow-up in women (7.7, 4.8-11.2 μg/mL; p < 0.001), but not in men. In the multiple regression analysis, high-density lipoprotein cholesterol levels and body weight were independent predictors of HMW adiponectin levels. The rate of change in HMW adiponectin levels was inversely correlated with the rates of change in body weight, body mass index, and knee leg extension strengths, and positively correlated with rates of change in high-density lipoprotein cholesterol and one-leg standing time. There were no significant differences in HMW adiponectin levels among SNPs.

DISCUSSION

Decreasing HMW adiponectin levels might lead to an increased risk of cardiovascular diseases in elderly women.

CONCLUSION

HMW adiponectin levels significantly decreased over a 5-year period in community-dwelling elderly Japanese women.

Leptin and adiponectin as new markers of undernutrition in cancer

OBJECTIVES

To evaluate leptin and adiponectin as markers of undernutrition in cancer patients, and compare their performances with those of other biomarkers.

DESIGN AND METHODS

This was a prospective and observational study of 132 patients with various types of cancer. Following the recommended professional criteria, we diagnosed undernutrition at the time of blood sampling for the biological analysis of leptin, adiponectin, paraoxonase (hydrolysis rate of three substrates: paraoxon (PON), phenylacetate (ARE) and thiolactone (LAC)), and the calculation of the Prognostic Inflammatory and Nutritional Index (PINI). Patients were monitored for one year to establish the mortality rate of the group. Relationships between biological variables and undernutrition were evaluated using univariate and multivariate logistic regression models. The Kaplan Meier method was used to analyse survival curves. Hazard ratios for death were calculated according to the quartiles of each biological variable.

RESULTS

In the case of undernutrition, a decrease was observed in levels of leptin and in the lactonase activity (LAC) of paraoxonase, while adiponectin levels increased. Besides PINI, leptin was the only parameter that was independently related to undernutrition. While no relation was found between survival and leptin or adiponectin levels, evidence was found that PINI, LAC and ARE were associated with survival, even in multivariate analysis.

CONCLUSIONS

Leptin and PINI are good markers of installed undernutrition, and PINI and ARE or LAC are reliable markers of the risk of death in patients suffering from cancer.

Higher Leptin and Adiponectin Concentrations Predict Poorer Performance-based Physical Functioning in Midlife Women: the Michigan Study of Women's Health Across the Nation

BACKGROUND

Excess fat mass is a greater contributor to functional limitations than is reduced lean mass or the presence of obesity-related conditions. The impact of fat mass on physical functioning may be due to adipokines, adipose-derived proteins that have pro- or anti-inflammatory properties.

METHODS

Serum samples from 1996 to 2003 that were assayed for leptin, adiponectin, and resistin were provided by 511 participants from the Michigan site of the Study of Women's Health Across the Nation. Physical functioning performance was assessed annually during study visits from 1996 to 2003.

RESULTS

Among this population of Black and White women (mean baseline age = 45.6 years, SD = 2.7 years), all of whom were premenopausal at baseline, higher baseline leptin concentrations predicted longer stair climb, sit-to-rise, and 2-pound lift times and shorter forward reach distance (all p < .01). This relationship persisted after adjustment for age, BMI, percent skeletal muscle mass, race/ethnicity, economic strain, bodily pain, diabetes, knee osteoarthritis, and C-reactive protein. Baseline total adiponectin concentrations did not predict any mobility measures but did predict quadriceps strength; a 1 µg/mL higher adiponectin concentration was associated with 0.64 Nm lower quadriceps strength (p = .02). Resistin was not associated with any of the physical functioning performance measures. Change in the adipokines was not associated with physical functioning.

CONCLUSION

In this population of middle-aged women, higher baseline leptin concentrations predicted poorer mobility-based functioning, whereas higher adiponectin concentrations predicted reduced quadriceps strength. These findings suggest that the relationship between the adipokines and physical functioning performance is independent of other known correlates of poor functioning.

High circulating adiponectin levels predict decreased muscle strength among older adults aged 70 years and over: A prospective cohort study

BACKGROUND AND AIMS

Population-based researches indicate that circulating adiponectin is inversely associated with muscle strength. However, interpretation of the findings has been limited by the use of a cross-sectional design. This study aimed to examine the prospective relationship between baseline circulating adiponectin concentration and change in muscular function-related physical performance in older adults.

METHODS AND RESULTS

A 1-year prospective cohort study of Japanese community-dwelling elderly was conducted between 2002 and 2003. Four hundred thirty-four older persons participated in the measurements of physical function, including leg extension power, functional reach, timed up-and-go test, and 10-m maximum walking speed, at baseline and follow-up. After adjustment for potential covariates, higher serum adiponectin concentration was found to be significantly associated with poorer physical performance at baseline (leg extension power [watt], P < 0.001; functional reach [cm], P < 0.001; log timed up-and-go test, P = 0.007; log 10-m maximum walking speed, P < 0.001). The results of the prospective analysis by analysis of covariance indicated that the elderly with higher serum adiponectin concentrations (tertiles) at baseline tended to have a decreased performance in leg extension power (means [95% confidence interval]: lowest, -105 [-125, -85.7]; middle, -117 [-135, -97.8]; highest, -140 [-160, -120], watt, P for trend = 0.021) and timed up-and-go test (lowest, -0.08 [-0.28, -0.12]; middle, -0.10 [-0.29, 0.10]; highest, 0.28 [0.07, 0.48], s, P for trend = 0.019), but not two other functioning.

CONCLUSION

High circulating adiponectin concentration may be an indicator of decreased physical performance, especially muscle strength, in older adults.

Omentin-1 promotes the growth of neural stem cells via activation of Akt signaling

Omentin is a novel adipokine, which is expressed in and released from omental adipose tissue. In the present study, the effect of omentin on neural stem cells (NSCs) was investigated. NSCs are a subtype of stem cell in the nervous system, which are able to self‑renew and generate neurons and glia for repairing neural lesions. Mouse NSCs were isolated and cultured in vitro. Treatment with recombinant omentin for 3 and 5 days significantly increased the size of NSC neurospheres (P<0.01) and enhanced NSC cell viability in normal conditions. In addition, omentin protected against the decrease in cell viability induced by the pro‑inflammatory cytokine tumor necrosis factor‑α. In the NSCs, incubation of omentin for 2, 4, 6, 8 and 16 h enhanced the phosphorylation of Akt at the Thr308 site and of AS160 at the Ser318 site, peaking 6 h after treatment. Additionally, treatment with LY294002 (10 µM), a specific inhibitor of phosphatidylinositol 3‑kinase/Akt signaling, eliminated the omentin‑induced increase in neurosphere size and cell viability. Overall, the present study provided the first evidence, to the best of our knowledge, that omentin promotes the growth and survival of NSCs in vitro through activation of the Akt signaling pathway. These results may contribute to the understanding of the role of omentin in the nervous system.

Serum adiponectin is associated with worsened overall survival in a prospective cohort of hepatocellular carcinoma patients

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. The rise in metabolic syndrome has contributed to this trend. Adipokines, such as adiponectin, are associated with prognosis in several cancers, but have not been well studied in HCC.

METHODS

We prospectively enrolled 140 patients with newly diagnosed or recurrent HCC with Child-Pugh (CP) class A or B cirrhosis. We examined associations between serum adipokines, clinicopathological features of HCC, and time to death. We also examined a subset of tumors with available pathology for tissue adiponectin receptor (AR) expression by immunohistochemistry.

RESULTS

The median age of subjects was 62 years; 79% were men, 59% had underlying hepatitis C, and 36% were diabetic. Adiponectin remained a significant predictor of time to death (hazard ratio 1.90; 95% confidence interval 1.05-3.45; p = 0.03) in a multivariable adjusted model that included age, alcohol history, CP class, stage, and serum α-fetoprotein level. Cytoplasmic AR expression (AR1 and AR2) in tumors trended higher in those with higher serum adiponectin levels and in those with diabetes mellitus, but the association was not statistically significant.

CONCLUSIONS

In this hypothesis-generating study, we found the serum adiponectin level to be an independent predictor of overall survival in a diverse cohort of HCC patients.

IMPACT

Understanding how adipokines affect the HCC outcome may help develop novel treatment and prevention strategies.

Associations of BMI and adipose tissue area and density with incident mobility limitation and poor performance in older adults

BACKGROUND

Obesity is a risk factor for disability, but risk of specific adipose depots is not completely understood.

OBJECTIVE

We investigated associations between mobility limitation, performance, and the following adipose measures: body mass index (BMI) and areas and densities of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) in older adults.

DESIGN

This was a prospective population-based study of men (n = 1459) and women (n = 1552) initially aged 70-79 y and free from mobility limitation. BMI was determined from measured height and weight. Adipose tissue area and density in Hounsfield units were measured in the thigh and abdomen by using computed tomography. Mobility limitation was defined as 2 consecutive reports of difficulty walking one-quarter mile or climbing 10 steps during semiannual assessments over 13 y. Poor performance was defined as a gait speed <1 m/s after 9 y of follow-up (n = 1542).

RESULTS

In models adjusted for disability risk factors, BMI, and areas of VAT, abdominal SAT, and IMAT were positively associated with mobility limitation in men and women. In women, thigh SAT area was positively associated with mobility limitation risk, whereas VAT density was inversely associated. Associations were similar for poor performance. BMI and thigh IMAT area (independent of BMI) were particularly strong indicators of incident mobility limitation and poor performance. For example, in women, the HR (95% CI) and OR (95% CI) associated with an SD increment in BMI for mobility limitation and poor performance were 1.31 (1.21, 1.42) and 1.41 (1.13, 1.76), respectively. In men, the HR (95% CI) and OR (95% CI) associated with an SD increment in thigh IMAT for mobility limitation and poor performance were 1.37 (1.27, 1.47) and 1.54 (1.18, 2.02), respectively.

CONCLUSIONS

Even into old age, higher BMI is associated with mobility limitation and poor performance. The amount of adipose tissue in abdominal and thigh depots may also convey risk beyond BMI.

Inverse association between circulating adiponectin levels and skeletal muscle strength in Japanese men and women

BACKGROUND AND AIMS

Increased levels of circulating adiponectin in the elderly cause a negative impact on physical function and health status, which suggests that circulating adiponectin may be related to skeletal muscle function. However, data on the relationship between circulating adiponectin levels and skeletal muscle function is limited. Our objective was to investigate the association between serum adiponectin levels and muscle strength in adults.

METHODS AND RESULTS

This cross-sectional study is a part of the Oroshisho Study of adult employees in Japan from 2008 to 2011. In our study, we used data gathered in 2008-2010 that had included serum adiponectin measurements (n = 1378; age, 19-83 years). From this population, 1259 subjects were evaluated for grip strength (949 men, 310 women), and 965 subjects were evaluated for leg extension power (716 men, 249 women). Multivariate linear regression analyses showed that adiponectin was associated significantly and negatively with both grip strength (β and standard error [SE]: men, -0.09 [0.01], p = 0.010; women, -0.20 [0.03], kg, p = 0.002) and leg extension power (men, -0.09 [0.02], p = 0.014; women, -0.14 [0.07], W, p = 0.032) after adjusting for age, physical activity, nutrient intake, depressive symptoms, metabolic syndrome, C-reactive protein, body mass index, and other lifestyle-related potential confounders.

CONCLUSION

This population-based cross-sectional study indicates an inverse association between serum adiponectin levels and muscle strength in adults. Further studies are necessary to confirm this association and to clarify causality.

Aging-induced dysregulation of dicer1-dependent microRNA expression impairs angiogenic capacity of rat cerebromicrovascular endothelial cells

Age-related impairment of angiogenesis is likely to play a central role in cerebromicrovascular rarefaction and development of vascular cognitive impairment, but the underlying mechanisms remain elusive. To test the hypothesis that dysregulation of Dicer1 (ribonuclease III, a key enzyme of the microRNA [miRNA] machinery) impairs endothelial angiogenic capacity in aging, primary cerebromicrovascular endothelial cells (CMVECs) were isolated from young (3 months old) and aged (24 months old) Fischer 344 × Brown Norway rats. We found an age-related downregulation of Dicer1 expression both in CMVECs and in small cerebral vessels isolated from aged rats. In aged CMVECs, Dicer1 expression was increased by treatment with polyethylene glycol-catalase. Compared with young cells, aged CMVECs exhibited altered miRNA expression profile, which was associated with impaired proliferation, adhesion to vitronectin, collagen and fibronectin, cellular migration (measured by a wound-healing assay using electric cell-substrate impedance sensing technology), and impaired ability to form capillary-like structures. Overexpression of Dicer1 in aged CMVECs partially restored miRNA expression profile and significantly improved angiogenic processes. In young CMVECs, downregulation of Dicer1 (siRNA) resulted in altered miRNA expression profile associated with impaired proliferation, adhesion, migration, and tube formation, mimicking the aging phenotype. Collectively, we found that Dicer1 is essential for normal endothelial angiogenic processes, suggesting that age-related dysregulation of Dicer1-dependent miRNA expression may be a potential mechanism underlying impaired angiogenesis and cerebromicrovascular rarefaction in aging.

Circulating factors induced by caloric restriction in the nonhuman primate Macaca mulatta activate angiogenic processes in endothelial cells

Moderate caloric restriction (CR) without malnutrition increases healthspan in virtually every species studied, including nonhuman primates. In mice, CR exerts significant microvascular protective effects resulting in increased microvascular density in the heart and the brain, which likely contribute to enhanced tolerance to ischemia and improved cardiac performance and cognitive function. Yet, the underlying mechanisms by which CR confer microvascular protection remain elusive. To test the hypothesis that circulating factors triggered by CR regulate endothelial angiogenic capacity, we treated cultured human endothelial cells with sera derived from Macaca mulatta on long-term (over 10 years) CR. Cells treated with sera derived from ad-libitum-fed control monkeys served as controls. We found that factors present in CR sera upregulate vascular endothelial growth factor (VEGF) signaling and stimulate angiogenic processes, including endothelial cell proliferation and formation of capillary-like structures. Treatment with CR sera also tended to increase cellular migration (measured by a wound-healing assay using electric cell-substrate impedance sensing [ECIS] technology) and adhesion to collagen. Collectively, we find that circulating factors induced by CR promote endothelial angiogenic processes, suggesting that increased angiogenesis may be a potential mechanism by which CR improves cardiac function and prevents vascular cognitive impairment.