Inverse relationship between serum hsCRP concentration and hand grip strength in older adults: a nationwide population-based study

Unlocking the potential of exercise: harnessing myokines to delay musculoskeletal aging and improve cognitive health

Objectives

This review aims to summarize the common physiological mechanisms associated with both mild cognitive impairment (MCI) and musculoskeletal aging while also examining the relevant literature on how exercise regulation influences the levels of shared myokines in these conditions.

Methods

The literature search was conducted via databases such as PubMed (including MEDLINE), EMBASE, and the Cochrane Library of Systematic Reviews. The searches were limited to full-text articles published in English, with the most recent search conducted on 16 July 2024. The inclusion criteria for this review focused on the role of exercise and myokines in delaying musculoskeletal aging and enhancing cognitive health. The Newcastle‒Ottawa Scale (NOS) was utilized to assess the quality of nonrandomized studies, and only those studies with moderate to high quality scores, as per these criteria, were included in the final analysis. Data analysis was performed through narrative synthesis.

Results

The primary outcome of this study was the evaluation of myokine expression, which included IL-6, IGF-1, BDNF, CTSB, irisin, and LIF. A total of 16 studies involving 633 older adults met the inclusion criteria. The current exercise modalities utilized in these studies primarily consisted of resistance training and moderate-to high-intensity cardiovascular exercise. The types of interventions included treadmill training, elastic band training, aquatic training, and Nordic walking training. The results indicated that both cardiovascular exercise and resistance exercise could delay musculoskeletal aging and enhance the cognitive functions of the brain. Additionally, different types and intensities of exercise exhibited varying effects on myokine expression.

Conclusion

Current evidence suggests that exercise mediates the secretion of specific myokines, including IL-6, IGF-1, BDNF, CTSB, irisin, and LIF, which establish self-regulatory circuits between the brain and muscle. This interaction enhances cognitive function in the brain and improves skeletal muscle function. Future research should focus on elucidating the exact mechanisms that govern the release of myokines, the correlation between the intensity of exercise and the secretion of these myokines, and the distinct processes by which myokines influence the interaction between muscle and the brain.

Emerging role of liver-bone axis in osteoporosis

Background

Increasing attention to liver-bone crosstalk has spurred interest in targeted interventions for various forms of osteoporosis. Liver injury induced by different liver diseases can cause an imbalance in bone metabolism, indicating a novel regulatory paradigm between the liver and bone. However, the role of the liver-bone axis in both primary and secondary osteoporosis remains inadequately elucidated. Therefore, exploring the exact regulatory mechanisms of the liver-bone axis may offer innovative clinical approaches for treating diseases associated with the liver and bone.

Methods

Here, we summarize the latest research on the liver-bone axis by searching the PubMed and Web of Science databases and discuss the possible mechanism of the liver-bone axis in different types of osteoporosis. The literature directly reporting the regulatory role of the liver-bone axis in different types of osteoporosis from the PubMed and Web of Science databases has been included in the discussion of this review (including but not limited to the definition of the liver-bone axis, clinical studies, and basic research). In addition, articles discussing changes in bone metabolism caused by different etiologies of liver injury have also been included in the discussion of this review (including but not limited to clinical studies and basic research).

Results

Several endocrine factors (IGF-1, FGF21, hepcidin, vitamin D, osteocalcin, OPN, LCAT, Fetuin-A, PGs, BMP2/9, IL-1/6/17, and TNF-α) and key genes (SIRT2, ABCB4, ALDH2, TFR2, SPTBN1, ZNF687 and SREBP2) might be involved in the regulation of the liver-bone axis. In addition to the classic metabolic pathways involved in inflammation and oxidative stress, iron metabolism, cholesterol metabolism, lipid metabolism and immunometabolism mediated by the liver-bone axis require more research to elucidate the regulatory mechanisms involved in osteoporosis.

Conclusion

During primary and secondary osteoporosis, the liver-bone axis is responsible for liver and bone homeostasis via several hepatokines and osteokines as well as biochemical signaling. Combining multiomics technology and data mining technology could further advance our understanding of the liver-bone axis, providing new clinical strategies for managing liver and bone-related diseases.The translational potential of this article is as follows: Abnormal metabolism in the liver could seriously affect the metabolic imbalance of bone. This review summarizes the indispensable role of several endocrine factors and biochemical signaling pathways involved in the liver-bone axis and emphasizes the important role of liver metabolic homeostasis in the pathogenesis of osteoporosis, which provides novel potential directions for the prevention, diagnosis, and treatment of liver and bone-related diseases.

The association between dietary inflammation index and bone mineral density: results from the United States National Health and nutrition examination surveys

OBJECTIVE

To investigate the associations of dietary inflammation index (DII) with bone density and osteoporosis in different femoral areas.

METHODS

The study population was selected from the National Health and Nutrition Examination Survey (NHANES) with the exclusion criteria of age 18, pregnancy, or missing information on DII, femoral bone marrow density (BMD), estimated glomerular filtration rate (eGFR), and urine albumin-to-creatinine ratio (UACR), or had diseases which may influence systemic inflammation. DII was calculated based on the questionnaire interview of dietary recall within 24 h. Subjects' baseline characteristics were collected. The associations between DII and different femoral areas were analyzed.

RESULTS

After applying exclusion criteria, 10,312 participants were included in the study. Significant differences among DII tertiles were found in BMD or T scores (p < .001) of the femoral neck, the trochanter, the intertrochanter, and the total femur. High DII was associated with low BMDs and T scores in all the femoral areas (all p < .01). Compared to low DII (tertile1, DII < 0.380 as reference), in the femoral neck, the intertrochanter, and the total femur, increased DII is independently associated with increased the possibility of the presence of osteoporosis (OR, 95% CI: 1.88, 1.11-3.20; 2.10, 1.05-4.20; 1.94, 1.02-3.69, respectively). However, this positive association was only observed in the trochanteric area of the non-Hispanic White population after full adjustment (OR, 95% CI: 3.22 (1.18, 8.79)). No significant difference in the association of DII and the presence of osteoporosis were found in subjects with or without impaired kidney function (eGFR < 60 ml/min/1.73 m²).

CONCLUSION

High DII is independently related to declined femoral BMD of femoral areas.

Dynapenia, Muscle Quality, and Hepatic Steatosis in Patients with Obesity and Sarcopenic Obesity

Accumulating evidence supports a connection between sarcopenic obesity (SO) and NAFLD. The extent to which fatty liver contributes to impaired muscle contractility is not yet well established. The aim of our study was to investigate the effect of NAFLD on dynapenia in patients with SO. In this study, 71 non-diabetic subjects (age 55 (7.8) years, BMI 35.2 kg/m² (32.6-38.8)) were classified as having SO and non-sarcopenic obesity (NSO). SO patients displayed worse serum lipid profiles, higher body fat, and lower skeletal muscle mass (both total and appendicular) than NSO patients, despite the absence of any significant differences in body weight, glycometabolic parameters, and hepatic steatosis prevalence. A positive correlation between disposition index and muscle quality index (MQI) (r = 0.393, p = 0.013) emerged after controlling for menopause and body fat percentage. Based on multiple linear regression analysis, MQI was significantly positively associated with the disposition index (β: 0.059, SE: 0.002, p = 0.006) after adjustment for menopause, body fat percentage, and the presence of hepatic steatosis according to the hepatorenal index (HRI). Similar findings emerged when including liver enzyme levels in place of hepatic steatosis. Muscle quality was positively associated with β-cell function corrected for insulin resistance among patients with obesity and sarcopenic obesity, irrespective of the presence of fatty liver disease.

Association between Handgrip Strength and the Systemic Immune-Inflammation Index: A Nationwide Study, NHANES 2011-2014

(1) Background: The Systemic immune-inflammatory index (SII) has been proven to be an effective biomarker of human immune and inflammatory levels and has prognostic significance for most diseases. Handgrip strength (HGS) is a simple and low-cost strength measurement method, which is not only highly correlated with overall muscle strength but also accurately and reliably predicts the risk of multiple chronic diseases and mortality; (2) Purpose: Association between HGS and the SII is unclear. The purpose of this study was to investigate the association between HGS and the SII in American adults; (3) Methods: We used the data from the 2011-2012 and 2013-2014 cycles of the National Health and Nutrition Examination Survey (NHANES), involving a total of 8232 American adults (aged 18-80 years). The SII was calculated as the Platelet count × Neutrophil count/Lymphocyte count; HGS was recorded as the ratio of the sum of the highest grip-strength values of each hand to body mass index taken as the relative grip strength. A weighted generalized linear regression model and analysis of restricted cubic spline regression, adjusted for confounding factors, were used in this study to assess associations between HGS and the SII in American adults; (4) Results: There was a negative correlation between the HGS and the SII of different sexes (p < 0.05), and there was a significant negative nonlinear relationship between the HGS and the SII in males (p for nonlinear = 0.0035), and the SII showed a downward trend with the increase in the HGS in males (Q2: β = -61.03, p = 0.01; Q3: β = -61.28, p = 0.04, Q4: β = -64.36, p = 0.03, p for trend = 0.04), when the HGS exceeds 3.16, with the HGS increasing, the downward trend of increasing the SII slowed down. The nonlinear relationship between the HGS and the SII in females was not significant (p for nonlinear = 0.1011), and the SII showed a linear downward trend with the increase in the HGS (Q2: β = -24.91, p = 0.25; Q3: β = -62.01, p = 0.03, Q4: β = -74.94, p = 0.03, p for trend = 0.01); (5) Conclusions: HGS is inversely and independently associated with SII levels, and although the limited cubic spline regression analysis showed gender differences, the overall trend of the HGS and the SII in different genders was consistent, with both showing that the SII decreased with increasing the HGS. In addition, HGS has high general applicability based on its ease of measurement; it is possible to understand one's own grip-strength level through routine grip-strength tests, and to make preliminary predictions on the current level of immunity and inflammation in the body.

Association Between C-Reactive Protein and Relative Handgrip Strength in Postmenopausal Korean Women Aged 45-80 Years: A Cross-Sectional Study

Background

Chronic inflammation plays a key role in the pathophysiology of frailty and loss of physical performance, which are closely associated with sarcopenia. In women, the decline in muscle mass and strength is accelerated after menopause. Thus, we examined the association between high sensitivity C-reactive protein (hs-CRP) and relative handgrip strength (HGS) in postmenopausal women.

Methods

This cross-sectional study included 2171 postmenopausal women aged ≥45 years who participated in the Korean National Health and Nutrition Survey (KNHNES) between 2015 and 2018. Relative HGS was categorized into quartiles as follows: Q1, <0.810 (kg/BMI); Q2, 0.810–0.968 (kg/BMI); Q3, 0.969–1.119 (kg/BMI); Q4, >1.119 (kg/BMI). The odds ratios (ORs) and 95% confidence intervals (95% CIs) for high hs-CRP (>1.0 mg/L, 75 percentile of the current samples) were calculated across relative HGS quartiles using multiple logistic regression analysis.

Results

The prevalence of high hs-CRP decreased with relative HGS quartiles. Compared to the highest quartile, the OR (95% CI) of the lowest relative HGS quartile for high hs-CRP was 3.266 (2.227–4.789) after adjusting for age, hypertension, diabetes mellitus, dyslipidemia, education, household income, physical activity, strength exercise, smoking, and alcohol ingestion.

Conclusion

Serum hs-CRP level was inversely and independently associated with relative HGS. Our findings indicate that low-grade inflammation is inversely associated with muscle strength in postmenopausal women.

Adherence to Mediterranean diet and its associations with circulating cytokines, musculoskeletal health and incident falls in community-dwelling older men: The Concord Health and Ageing in Men Project

BACKGROUND & AIMS

Mediterranean dietary patterns may exert favourable effects on various health conditions. This study aimed to determine associations of adherence to Mediterranean diet as well as its components, with circulating cytokine levels, musculoskeletal health and incident falls in community-dwelling older men.

METHODS

Seven hundred ninety-four (794) community-dwelling men with mean age 81.1 ± 4.5 years, who participated in the five-year follow-up of the Concord Health and Ageing in Men Project (CHAMP) were included in the cross-sectional analysis, and 616 attended follow-up three years later. Adherence to Mediterranean diet was assessed using MEDI-LITE (literature-derived Mediterranean diet) score which was obtained using a validated diet history questionnaire. Twenty-four evaluable circulating cytokines were analyzed using Bio-Plex Pro Human Cytokine 27-plex Assay kit. Appendicular lean mass (ALM) and bone mineral density (BMD) were measured using dual-energy x-ray absorptiometry (DXA). Three-year changes in gait speed and hand grip strength were assessed by walking a 6-m course and using a dynamometer respectively and analyzed using linear mixed-effects models. Incident falls over three years were determined through telephone interviews every four months. Multivariable linear regression was utilized to determine the cross-sectional associations between MEDI-LITE scores and circulating cytokines, bone mineral density, ALM, and ALM_BMI. Linear mixed-effects models were performed to estimate associations between MEDI-LITE scores and three-year change in hand grip strength and gait speed while negative binomial regression was applied to estimate associations between MEDI-LITE scores and three-year incident falls as well as associations between each MEDI-LITE component and three-year incident falls. Adjustments for multiple comparisons were performed using Benjamini-Hochberg adjustment for multiple testing.

RESULTS

A higher MEDI-LITE score, indicating greater adherence to Mediterranean diet, was associated with higher appendicular lean mass adjusted for body mass index (ALM_BMI) (β: 0.004 kg; 95% CI: 0.000, 0.008), and lower incident falls rates (IRR: 0.94; 95% CI: 0.89, 0.99). Higher consumption of monounsaturated fatty acids (IRR: 0.76; 95% CI: 0.59, 0.98) and monounsaturated fatty acids to saturated fatty acids ratio (IRR: 0.72; 95% CI: 0.57, 0.90) were associated with 24%, and 28% lower falls risk in older men respectively. MEDI-LITE scores were not associated with BMD or physical function parameters.

CONCLUSIONS

Adherence to a Mediterranean diet is associated with higher ALM_BMI, and fewer falls in community-dwelling older men. Monounsaturated and saturated fatty acids were the most important contributors to the association between Mediterranean diet and falls risk.

Association of circulating C-reactive protein and high-sensitivity C-reactive protein with components of sarcopenia: A systematic review and meta-analysis of observational studies

BACKGROUND

Sarcopenia, a multi-faceted skeletal muscle disorder in the older population, has poor health outcomes. Some previous observational studies investigated the association between circulating inflammatory markers and sarcopenia components to evaluate chronic inflammation as a risk factor for sarcopenia in the elderly population. Nevertheless, the association between circulating C-reactive protein (CRP) and hs-CRP, as the recognized markers of systemic inflammation and components of sarcopenia, is unclear. This meta-analysis aimed to investigate the association of muscle strength, muscle mass, and muscle function with two serum inflammatory markers, circulating C-reactive protein (CRP) and high-sensitive CRP (hs-CRP).

METHODS

We assessed all observational studies across different electronic databases including PubMed, Scopus, and Google Scholar using keywords such as "muscle strength", "muscle mass", "muscle function", CRP and hs-CRP from inception until the 30th of July 2019. Only studies that investigated the association between components of sarcopenia and CRP or hs-CRP levels were included. Participants' country, age, sex, BMI, and screening tool for sarcopenia were retrieved. The correlations between muscle strength, muscle mass, and muscle function with CRP, and hs-CRP were expressed as the correlation coefficient (r) with 95% confidence intervals (CIs). Begg's test and Egger's test were conducted to evaluate risk of publication bias in this study.

RESULTS

Initially, we found fifty-nine studies for the qualitative synthesis. Ultimately, nineteen adult cross-sectional studies comprising 14,650 subjects were included in the meta-analysis. Of them, fourteen studies measured the correlation between CRP or hs-CRP and muscle strength. There were significant inverse correlation between CRP and hs-CRP concentrations with muscle strength (ES (z) = -0.22; 95% CI = -0.34 to -0.09; P < 0.001), (ES (z) = -0.22; 95% CI = -0.34 to -0.09; P < 0.001), respectively. No publication bias was found between muscle strength and CRP (P = 0.53) or hs-CRP (P = 0.62) respectively.

CONCLUSION

Among diagnostic components of sarcopenia, impairment of muscle strength was independently associated with both inflammatory biomarkers. However, future cohort studies are essential to clarify the causal correlation.

Cardiometabolic Changes in Response to a Calorie-Restricted DASH Diet in Obese Older Adults

Objective: To examine the response of a calorie-restricted Dietary Approaches to Stop Hypertension diet on indicators of cardiometabolic health in a cohort of sedentary obese older adults. Design: This was a controlled-feeding trial with a parallel design. Each participant consumed either 3 oz (85 g; n = 15) or 6 oz (170.1 g; n = 13) of lean fresh beef within a standardized calorie-restricted DASH-like diet for 12-weeks. Fasted blood samples were collected and used to measure conventional biomarkers of cardiovascular, metabolic and inflammatory health. Participants: Caucasian older (70.8 years), obese (BMI: 32 ± 6.9 kg/m²; WC: 101 ± 16.4 cm) females (n = 17) and males (n = 11) from the rural community of Brookings, South Dakota. Results: 28 participants completed the 12-week feeding trial, with no differences (p > 0.05) among the biomarkers of cardiometabolic health between the 3 and 6 oz beef intake groups. However, when the beef intake groups were combined, all biomarkers changed concentration in response to the intervention diet. Total cholesterol (p < 0.001), LDL-C (p = 0.004), HDL-C (p < 0.0001), insulin (p = 0.014), glucose (p = 0.008), HOMA-IR (p < 0.05), IL-12 (p < 0.001), and CRP (p = 0.006) all decreased in response to the study diet. IGF-1 (p < 0.001) and IL-8 (p = 0.005) increased in response to the intervention. Correlations among cardiometabolic biomarkers and body composition measures were observed. By study end, the decrease in insulin (R ² = 0.22; P = 0.012) and HOMA-IR (R ² = 0.22; P = 0.01) was positively correlated with the decrease in waist circumference. The increase in IGF-1 was significantly correlated with the decrease in waist circumference (R ² = 0.21; p = 0.014). The increase in IGF-1 was significantly correlated with the increase in sit-to-stand (R ² = 0.21; p = 0.016). The increase in IL-8 was significantly correlated with decreases in total cholesterol (R ² = 0.24; P = 0.008), LDL-C (R ² = 0.17; P = 0.031) and glucose (R ² = 0.44; P = 0.0001). Conclusions: These findings suggest that a DASH-like diet with restricted calories may potentially improve biomarkers of cardiometabolic health in sedentary obese older adults. These results also point to interrelationships between body composition changes and changes in cardiometabolic biomarkers. Lastly, regardless of meat intake amount, positive impacts on cardiometabolic biomarkers were observed in this cohort of older adults with an obese phenotype.

Association between weekend catch-up sleep and high-sensitivity C-reactive protein levels in adults: a population-based study

STUDY OBJECTIVES

To investigate the association between weekend catch-up sleep (WCS) and the levels of high-sensitivity C-reactive protein (hsCRP)-a serum inflammatory maker-in adults.

METHODS

Data of 5,506 adults aged 19 years or older were obtained from the nationwide cross-sectional Korea National Health and Nutrition Examination Surveys conducted in 2016. Serum hsCRP level, weekday and weekend sleep durations, and sociodemographic and health-related characteristics were assessed. Participants whose weekend sleep duration was more than 1 h longer than their weekday sleep duration were included in the WCS group. hsCRP level was categorized into quartiles (i.e. highest, middle-high, middle-low, and lowest). Obesity was defined by body mass index ≥ 25.0 kg/m2.

RESULTS

The WCS group included 1,901 participants (34.5%). In the logistic regression analysis controlling for all variables, adults in the WCS group were significantly less likely to show the highest hsCRP level (versus the lowest level) compared with those without WCS in the complete sample (adjusted odds ratio = 0.795, 95% confidence interval [CI] = 0.662 to 0.955). In a subgroup analysis, this association was significant only for those with weekday sleep duration of 6 h or lower. Longer WCS (≥3 h) was not associated with hsCRP levels. Non-obese people with WCS demonstrated a lower risk for high hsCRP levels, while there was no significant difference in obese people with WCS.

CONCLUSIONS

Our findings indicate that WCS may be beneficial for low-grade systemic inflammation in adults, particularly among those with shorter weekday sleep durations. WCS may also interact with obesity.

Lower hand grip strength in older adults with non-alcoholic fatty liver disease: a nationwide population-based study

Although both liver and muscle are metabolically active endocrine organs, and non-alcoholic fatty liver disease (NAFLD) and sarcopenia may share common pathogenic determinants, there have been few clinical studies of the relationship between NAFLD and muscle strength, especially in the elderly. We conducted a nationally representative population-based, cross-sectional study using data from the Korea National Health and Nutrition Examination Survey, which involved 1,897 men aged ≥50 years and 2,206 postmenopausal women. NAFLD was defined using the hepatic steatosis index (HSI) and low muscle strength was defined using the Korea-specific cut-off point of hand grip strength (HGS). Men and women with NAFLD had 7.3% and 7.9% lower HGS than controls, respectively. The odds ratios for low muscle strength in the presence of NAFLD were 2.51 in men and 2.34 in women. HSI inversely correlated with HGS in both men and women. Consistently, compared with men and women in the lowest HSI quartile, those in the highest quartile had 7.6% and 12.4% lower HGS, respectively, and were 5.63- and 3.58-times more likely to have low muscle strength, respectively. These results provide the first clinical evidence that NAFLD can be associated with muscular impairment in older adults, as demonstrated by lower muscle strength.

Proinflammatory Diet Increases Circulating Inflammatory Biomarkers and Falls Risk in Community-Dwelling Older Men

BACKGROUND

The relations between diet, chronic inflammation, and musculoskeletal health are unclear, especially among older men.

OBJECTIVE

This study aimed to determine associations of the Dietary Inflammatory Index (DII) with inflammatory biomarkers, musculoskeletal health, and falls risk in community-dwelling older men.

METHODS

The cross-sectional analysis included 794 community-dwelling men, mean age 81.1 ± 4.5 y, who participated in the 5-y follow-up of the Concord Health and Aging in Men Project. Of these, 616 were seen again 3 y later for the longitudinal analysis. Energy-adjusted DII (E-DII) was calculated from a validated diet history questionnaire. Bone mineral density (BMD) was measured using DXA. Twenty-four inflammatory biomarkers were analyzed. Incident falls over 3 y were determined through telephone interviews every 4 mo. Multiple regression, linear mixed effects models, negative binomial regression, and mediation analysis were utilized in this study.

RESULTS

A higher E-DII score (indicating a more proinflammatory diet) was associated with higher concentrations of IL-6 (β: 0.028 pg/mL; 95% CI: 0.003, 0.053), IL-7 (β: 0.020 pg/mL; 95% CI: 0.002, 0.037), and TNF-α (β: 0.027 pg/mL; 95% CI: 0.003, 0.051). A higher E-DII score was also associated with lower appendicular lean mass adjusted for BMI (ALMBMI) (β: -0.006 kg/m2; 95% CI: -0.010, -0.001). For every unit increase in E-DII (range: -4.91 to +3.66 units), incident falls rates increased by 13% (incidence rate ratio: 1.13; 95% CI: 1.05, 1.21) over 3 y. Mediation analysis showed that the association between E-DII and 3-y incident falls was influenced by the concentrations of IL-7 by 24%. There was no association between E-DII and BMD.

CONCLUSIONS

Consumption of a proinflammatory diet was associated with increased concentrations of IL-6, IL-7, and TNF-α; increased falls risk; and lower ALMBMI in community-dwelling older men. The association between incident falls and E-DII was partly mediated by concentrations of IL-7.