Low relative skeletal muscle mass predicts incident hypertension in Korean men: a prospective cohort study

Association between myosteatosis or sarcopenia based on abdominal CT and hypertension in systemic lupus erythematosus patients

BACKGROUND

Hypertension and obesity are common in systemic lupus erythematosus (SLE) patients, with obesity-related changes potentially driving hypertension. However, the specific adiposity measures associated with hypertension in SLE patients remain unclear. This study assessed the association between myosteatosis and sarcopenia detected on abdominal CT and hypertension in SLE patients. Mediators of the association between myosteatosis and hypertension were also investigated.

METHODS

This was a retrospective study involving SLE patients enrolled from January 2017 to August 2023 and who underwent abdominal CT at the L3 level to track myosteatosis and sarcopenia based on the skeletal muscle mean radiodensity (SMD) and skeletal muscle index considered as binary and continuous variables. The association between these body composition measures and hypertension was tested using logistic regression analyses, while mediation modeling was used to assess the mediators.

RESULTS

A total of 279 adult SLE patients (median age, 41.00 [30.00, 51.00] years; 245 women) were included in this study. Hypertension was associated with myosteatosis (adjusted OR: 3.54; 95% CI: 1.18-10.61 for the binary variable and 1.31; 95% CI: 1.02-1.68 for the continuous variable). No statistically significant association was observed between hypertension and sarcopenia (adjusted OR: 0.48; 95%CI: 0.23-1.01 for the binary variable and 0.95; 95%CI: 0.78-1.16 for the continuous variable). Mediation analyses revealed eGFR could mediate the association between myosteatosis (considered as a continuous variable) and hypertension in SLE patients when taken alone (95% CI: 0.0177-0.2765) or in combination with the TyG index (95% CI: 0.0032-0.0614).

CONCLUSIONS

Myosteatosis was associated with hypertension in SLE patients. eGFR alone or in combination with the TyG index may mediate this association.

Sex and obesity influence the relationship between perfluoroalkyl substances and lean body mass: NHANES 2011-2018

Objective

Polyfluoroalkyl substances (PFAS) are known endocrine disruptors, that have been the subject of limited research regarding their impact on human lean body mass. The aim of this study was to investigate the effects of PFAS exposure on lean body mass.

Methods

We performed a cross-sectional data analysis involving 1022 adolescents and 3274 adults from the National Health and Nutrition Examination Survey (NHANES) 2011-2018, whose lean body mass was measured by dual-energy X-ray absorptiometry. The lean mass index (LMI) was calculated as lean body mass dividing by the square of height. The association between PFAS and LMI was examined through a multivariate-adjusted weighted generalized linear model. Moreover, weighted quantile sum (WQS) regression models were employed to futher examine the relationship between the mixture of PFAS and LMI.

Results

Regression analyses revealed an inverse correlation between PFAS exposure and LMI after adjusting for potential covariates. Adults with higher serum PFAS concentrations manifested a reduction in whole LMI ( β  = -0.193, 95 % confidence interval (CI): -0.325 to -0.06). Notably, this correlation was particularly significant in adult females and individuals with obesity, and it was observed across diverse anatomical regions, including lower limbs, right arm, trunk, and whole lean body mass. In adult females, the association between PFAS and whole LMI was statistically significant ( β  = -0.294, 95 % CI: -0.495 to -0.094), and a similar trend was found in obese individuals ( β  = -0.512, 95 % CI: -0.762 to -0.261). WQS regression analyses supported the results obtained from weighted linear regression analyses.

Conclusions

Our study suggests that exposure to PFAS, whether individually or in combination, is associated with decreased lean body mass in specific body areas, with sex and obesity serving as major influencing factors.

Sex-specific associations between total and regional Fat-to-muscle Mass ratio and cardiometabolic risk: findings from the China National Health Survey

BACKGROUND

The fat-to-muscle mass ratio (FMR), integrating the antagonistic effects of fat and muscle mass, has been suggested as a valuable indicator to assess cardiometabolic health independent of overall adiposity. However, the specific associations of total and regional FMR with cardiometabolic risk are poorly understood. We aimed to examine sex-specific associations of total and regional FMR with single and clustered cardiometabolic risk factors (CRFs).

METHODS

13,505 participants aged 20 years and above were included in the cross-sectional study. Fat mass and muscle mass were assessed using a bioelectrical impedance analysis device. FMR was estimated as fat mass divided by muscle mass in corresponding body parts (whole body, arm, leg, and trunk). Clustered CRFs was defined as the presence of two or more risk factors, including hypertension, elevated blood glucose, dyslipidemia, insulin resistance (IR), and hyperuricemia. IR was assessed by the triglyceride glucose (TyG) index. Multivariable logistic regression models were applied to explore the associations of FMR in the whole body and body parts with single and clustered CRFs.

RESULTS

The odds ratios (ORs) increased significantly for all single and clustered CRFs with the per quartile increase of total and regional FMR in both sexes (P for trend < 0.001), following adjustment for confounders. Among the regional parts, FMRs of the legs presented the strongest associations for clustered CRFs in both men and women, with adjusted OR of 8.54 (95% confidence interval (CI): 7.12-10.24) and 4.92 (95% CI: 4.24-5.71), respectively. Significant interactions (P for interaction < 0.05) were identified between age and FMRs across different body parts, as well as between BMI status and FMRs in different regions for clustered CRFs. Restricted cubic splines revealed significant non-linear relationships between FMRs of different body parts and clustered CRFs in both sexes (P for nonlinear < 0.05).

CONCLUSIONS

FMRs in the whole body and different regions were significantly associated with single and clustered CRFs in the general Chinese population. The association between FMR and clustered CRFs was more pronounced in youngers than in the elderly.

Sarcopenia as a Robust Predictor of Readmission within 6 Months among Individuals Experiencing Acute Stroke

BACKGROUND

Sarcopenia negatively affects the short-term prognosis of hospitalized older adults. However, no evidence currently supports a direct relationship between sarcopenia and readmission among individuals who have experienced an acute stroke. Therefore, we investigated whether sarcopenia is associated with readmission after discharge.

METHODS

This retrospective cohort study included patients who had experienced acute stroke. Sarcopenia was defined as the coexistence of low skeletal muscle mass index (SMI) and grip strength. We applied the log-rank test and Cox proportional hazards regression analysis to analyze whether sarcopenia, low SMI, and low grip strength were associated with readmission within 6 months.

RESULTS

Among 228 included patients (mean age, 72.8 years; 146 males), the prevalence of sarcopenia was 24.6% (n=56; male 17.8%; female 36.6%). Cox proportional hazards regression analysis using the propensity score as a covariate revealed that sarcopenia (hazard ratio [HR]=7.21; 95% confidence interval [CI] 1.45-35.8; p=0.016) and low skeletal muscle mass (HR=7.40; 95% CI 1.14-48.1; p=0.036), but not low grip strength (HR=1.42; 95% CI 0.281-7.21; p=0.670), were significantly associated with readmission for stroke within 6 months.

CONCLUSIONS

Sarcopenia was negatively associated with readmission within 6 months of stroke onset in patients in Japan who had experienced an acute stroke. These findings suggest that the identification of sarcopenia may facilitate prognostic prediction from the acute stage and intervention(s) to prevent rehospitalization.

Prevalence of hypertension and its associations with body composition across Chinese and American children and adolescents

BACKGROUND

The age of onset of hypertension (HTN) is decreasing, and obesity is a significant risk factor. The prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently studied. This study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and HTN.

METHODS

Seven thousand, five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8-18 years from the 2013-2015 China Child and Adolescent Cardiovascular Health study and the 2011-2018 National Health and Nutrition Examination Surveys were analyzed. Blood pressure and body composition (fat and muscle) were measured by trained staff. The crude prevalence and age-standardized prevalence rate (ASPR) of primary HTN and its subtypes [isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH)] were calculated based on 2017 American Academy of Pediatrics guidelines. Multivariable-adjusted linear regression coefficients and odds ratios (ORs) were calculated to assess the associations of body composition indicators with HTN, ISH and IDH.

RESULTS

The ASPR of HTN was 18.5% in China (CN) and 4.6% in the United States (US), whereas the obesity prevalence was 7.4% and 18.6%, and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in CN. Increased fat mass, muscle mass and body fat percentage mass were associated with a higher risk of HTN in both countries. The percent of muscle body mass had a protective effect on HTN and ISH in both countries [HTN (CN: OR = 0.83, 95% CI = 0.78-0.88; US: OR = 0.72, 95% CI = 0.64-0.81); ISH (CN: OR = 0.87, 95% CI = 0.80-0.94; US: OR = 0.71, 95% CI = 0.62-0.81)], and the protective effect was more common among children and adolescents with high levels of physical activity.

CONCLUSIONS

The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US, and the contribution of obesity to HTN was higher in the US than in CN. Augmenting the proportion of muscle mass in body composition has a protective effect against HTN in both populations. Optimizing body composition positively influences blood pressure in children and adolescents, particularly those with high-level physical activity. Video abstract (MP4 149982 KB).

The relationship between serum creatinine/cystatin C ratio and mortality in hypertensive patients

BACKGROUND AND AIMS

Sarcopenia is a disease characterized by loss of skeletal muscle mass and function that is closely associated with cardiovascular disease. The serum creatinine/cystatin C (Cr/CysC) ratio has been shown to be a simplified indicator for identifying low muscle mass (LMM) or sarcopenia. The aim of this study was to investigate whether the Cr/CysC ratio helps to predict prognostic information in hypertensive patients.

METHODS AND RESULTS

This cohort study included 2509 patients with hypertension from the National Health and Nutrition Survey 1999-2002. To evaluate the association between Cr/CysC ratio and mortality, we used Kaplan Meier estimates to calculate cumulative survival probabilities for all-cause mortality and cardiovascular mortality, Cox regression analyses, and hazard ratio (HR) and 95% confidence interval (CI) were calculated. Over a median follow-up of 11.76 years, lower Cr/CysC ratio was associated with lower risk of all-cause mortality (per 0.1 increase, HR:0.81, 95% CI: 0.77-0.85, P < 0.001) and cardiovascular mortality (per 0.1 increase, HR:0.80, 95% CI: 0.72-0.89, P < 0.001). Compared with patients with normal muscle mass, all-cause mortality, and cardiovascular mortality HR for patients with LMM diagnosed by Cr/CysC ratio were 1.57 (95% CI: 1.36-1.82, P < 0.001) and 1.64 (95% CI: 1.12-2.42, P = 0.012), respectively.

CONCLUSION

We found that low muscle mass shown by lower Cr/CysC ratio was an independent risk factor for poor prognosis in hypertensive patients. We recommend routine screening of Cr/CysC ratio in hypertensive patients and early intervention for low muscle mass or sarcopenia.

Muscle quality is negatively related to hypertension prevalence in adults: Results from NHANES 2011-2014

Resistance training could counter hypertension and improve muscle quality (MQ), but current evidence about the correlation between MQ and hypertension is limited. The authors aimed to explore this correlation using the data of participants aged 20-59 from NHANES 2011-2014 via a cross-sectional study. The MQ was quantified as handgrip strength (kg)/lean soft tissue mass (kg) of the dominant arm. Weighted multivariate logistic regression models were mainly utilized to investigate the MQ-hypertension association; linear trend tests and subgroup analysis were also conducted. Moreover, the authors employed weighted multivariate linear regression models to uncover the association between blood pressure (BP) and MQ. Four thousand four hundred and sixty-nine individuals were enrolled, and 1167 were hypertensive. Hypertensive participants had a lower MQ than normotensive participants. In the totally adjusted model, each unit elevation in MQ was related to a 7% reduction in hypertension prevalence (p =.002). There was a decreasing trend in hypertension prevalence and in systolic BP as the MQ increased from the bottom to the top quartile across all three models (p for trend ≤.01), with a 28% difference (OR: 0.72, 95% CI: 0.54, 0.95) in hypertension prevalence and a 1.88 mm Hg (95% CI: -3.56, -0.20) difference in SBP between the top and bottom quartiles in the fully adjusted model. Subgroup analysis further confirmed the MQ-hypertension inverse association. In conclusions, the MQ was negatively associated with hypertension prevalence and systolic BP, which suggests the MQ may be a protective factor for hypertension and need to be improved.

Association between relative muscle strength and hypertension in middle-aged and older Chinese adults

BACKGROUND

The association between muscle defects and hypertension is well-established. However, the absence of pertinent and uncomplicated clinical indicators presents a challenge. Relative muscle strength (RMS) may offer a viable indicator. This study aimed to explore the association between RMS and hypertension.

METHODS

A total of 12,720 individuals aged ≥ 45 years from the 2011 wave of the China Health and Retirement Longitudinal Study (CHARLS) were included. Grip strength was recorded and appendicular skeletal muscle mass (ASM) was estimated using a validated mathematical formula. The RMS was calculated as the ratio of grip strength to ASM. Hypertension was determined based on previous diagnosis, history of hypertension medication use, and current blood pressure. Logistic regression models were employed to investigate the relationship between RMS and hypertension.

RESULTS

The prevalence of hypertension was 41.7% (5,307/12,720 patients). RMS was negatively correlated with hypertension with an OR (95% CI) of 0.68 (0.59-0.79) for males, 0.81 (0.73-0.90) for females, and 0.78 (0.72-0.85) for the entire population after adjusting for related covariates including age, education, marital history, smoking history, drinking history, diabetes, hyperlipidemia, and obesity. The trend test showed a linear association among males, females, or the entire population. Stratified analysis showed a consistent negative correlation between RMS and hypertension.

CONCLUSIONS

Higher RMS is an independent protective factor against hypertension and efforts to promote RMS may be beneficial for the prevention and management of hypertension.

The relationship between skeletal muscle mass and the KOSHA cardiovascular risk in obese male workers

Background

Efforts for the prevention and management of cardiovascular diseases (CVDs) in workers have been actively pursued. Obesity is one of the important risk factors related to CVDs. Obesity has various metabolic characteristics, and some individuals can be metabolically healthy. Body composition including skeletal muscle mass is known to have protective effect in obesity. The study aims to investigate the association between skeletal muscle mass and Korea Occupational Safety and Health Agency (KOSHA) CVD risk among obese male manufacturing workers in Korea and to identify appropriate indicators of skeletal muscle mass for predicting risk of CVDs.

Methods

The study was conducted on 2,007 obese male workers at a manufacturing industry aged more than 19 years. Skeletal muscle mass, skeletal muscle index (SMI), skeletal muscle mass percent (SMM%) and skeletal muscle to body fat ratio (MFR) were used to evaluate body composition and these indicators were divided into quartiles. The odds ratios (ORs) and 95% confidence intervals (CIs) for the KOSHA CVD risk groups according to quartiles of skeletal muscle mass indicators were estimated using ordinal logistic regression analysis.

Results

The OR for the KOSHA CVD risk groups in the highest quartile of SMI was 1.67 (95% CI: 1.42-1.92), while the ORs for the KOSHA CVD risk groups in the highest quartiles of SMM%, SMM/body mass index (BMI), and MFR were 0.47 (95% CI: 0.22-0.72), 0.51 (95% CI: 0.05-0.76), and 0.48 (95% CI: 0.23-0.74), respectively.

Conclusions

We found that high SMI increase the likelihood of high risk of CVDs, while high SMM%, SMM/BMI, and MFR lower the likelihood of high risk of CVDs. Accurate evaluation of skeletal muscle mass can help assess the cardiovascular risk in obese male workers.

Negative association between triglyceride glucose index and BMI-adjusted skeletal muscle mass index in hypertensive adults

BACKGROUND

The triglyceride glucose (TyG) index, an indicator of insulin resistance, is often associated with adverse outcomes in various cardiovascular diseases, while hypertension is associated with an increased risk of cardiovascular diseases. As the loss of muscle mass in people with hypertension is poorly understood, the current study aimed to explore the relationship between TyG index and muscle mass in hypertensive population.

METHODS

We analyzed data from hypertensive adult participants in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018. The TyG index and body mass index (BMI)-adjusted skeletal muscle mass index (SMI) were calculated and the relationship between the two was evaluated using multivariable linear regression and restricted cubic spline (RCS) regression models.

RESULTS

A total of 1633 participants in the dataset were included for the final analysis. In the multivariable regression analysis, the adjusted β of SMI with a 95% confidence interval (CI) for the highest TyG index quartile was - 5.27 (- 9.79 to - 0.75), compared with the lowest quartile. A negative linear relationship between TyG index and SMI was plotted by RCS regression (nonlinear P = 0.128). Stratified models of non-smoking women of different ages also demonstrated that SMI decreased as TyG index increased (all P for trend < 0.05).

CONCLUSION

This linear and negative correlation between TyG index and SMI in hypertensive patients suggests that insulin resistance adversely affects muscle mass.

SARcopenia Assessment in Hypertension: The SARAH Study

OBJECTIVES

The aims of the study were to investigate the relationship between sarcopenia and renin-angiotensin system-related disorders and to explore the effects of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on muscle mass/function and physical performance.

DESIGN

This multicenter, cross-sectional study was performed using ISarcoPRM algorithm for the diagnosis of sarcopenia.

RESULTS

Of the 2613 participants (mean age = 61.0 ± 9.5 yrs), 1775 (67.9%) were hypertensive. All sarcopenia-related parameters (except chair stand test in males) were worse in hypertensive group than in normotensive group (all P < 0.05). When clinical/potential confounders were adjusted, hypertension was found to be an independent predictor of sarcopenia in males (odds ratio = 2.403 [95% confidence interval = 1.514-3.813]) and females (odds ratio = 1.906 [95% confidence interval = 1.328-2.734], both P < 0.001). After adjusting for confounding factors, we found that all sarcopenia-related parameters (except grip strength and chair stand test in males) were independently/negatively related to hypertension (all P < 0.05). In females, angiotensin-converting enzyme inhibitors users had higher grip strength and chair stand test performance values but had lower anterior thigh muscle thickness and gait speed values, as compared with those using angiotensin II receptor blockers (all P < 0.05).

CONCLUSIONS

Hypertension was associated with increased risk of sarcopenia at least 2 times. Among antihypertensives, while angiotensin-converting enzyme inhibitors had higher muscle function values, angiotensin II receptor blockers had higher muscle mass and physical performance values only in females.

Increased Dietary Niacin Intake Improves Muscle Strength, Quality, and Glucose Homeostasis in Adults over 40 Years of Age

BACKGROUND AND AIMS

Age-related loss of skeletal muscle mass and strength begins at 40 years of age, and limited evidence suggests that niacin supplementation increases levels of nicotinamide adenine dinucleotide in mouse muscle tissue. In addition, skeletal muscle has a key role in the body's processing of glucose. Therefore, this study aimed to investigate the relationship between dietary niacin and skeletal muscle mass, strength, and glucose homeostasis in people aged 40 years and older.

METHODS

This study was an American population-based cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES). Considering that some outcomes are only measured in specific survey cycles and subsamples, we established three data sets: a grip strength dataset (2011-2014, n=3772), a body mass components dataset (2011-2018, n=3279), and a glucose homeostasis dataset (1999-2018, n=9189). Dietary niacin and covariates were measured in all survey cycles. Linear regression or logistic regression models that adjusted for several main covariates, such as physical activity and diet, was used to evaluate the relationship between dietary niacin and grip strength, total lean mass, appendicular lean mass, total fat, trunk fat, total bone mineral content, homeostasis model assessment of insulin resistance (HOMA-IR), fasting blood glycose, fasting insulin and sarcopenia risk. Subgroup analyses, a trend test, an interaction test, and a restricted cubic spline were used for further exploration.

RESULTS

Higher dietary niacin intake was significantly correlated with higher grip strength (β 0.275, 95% confidence intervals [CI] 0.192-0.357), higher total lean mass (β 0.060, 95% CI 0.045-0.074), higher appendicular lean mass (β 0.025, 95% CI 0.018-0.033), and higher total bone mineral content (β 0.005, 95% CI 0.004-0.007). By contrast, higher dietary niacin intake was significantly associated with lower total fat (β -0.061, 95% CI -0.076 to -0.046), lower trunk fat (β -0.041, 95% CI -0.050 to -0.032) and lower sarcopenia risk (OR 0.460, 95% CI 0.233 to 0.907). In addition, dietary niacin significantly reduced HOMA-IR, fasting blood glucose (in participants without diabetes), and fasting insulin (p <0.05).

CONCLUSION

Niacin is associated with improved body composition (characterized by increased muscle mass and decreased fat content) and improved glucose homeostasis in dietary doses. Dietary niacin supplementation is a feasible way to alleviate age-related muscular loss.

Relationship between hyperhomocysteinemia and coexisting obesity with low skeletal muscle mass in asymptomatic adult population

The relationship between hyperhomocysteinemia (HHcy) and obesity with low skeletal muscle mass (LMM) has not been established. We aim to assess the association between HHcy and the coexistence of obesity and LMM in asymptomatic adult population. We conducted a population-based cross-sectional study among asymptomatic individuals who underwent measurements of plasma homocysteine and body composition analysis. HHcy was defined as > 15 umol/L, obesity as body mass index ≥ 25 (kg/m²), and LMM as skeletal muscle index less than 2 SD below the sex-specific mean of young adults. The participants were classified into ‘control’, ‘obesity alone’, ‘LMM alone’, and ‘obesity with LMM’. Among 113,805 participants, the prevalence of HHcy was 8.3% in control, 8.7% in obesity alone, 10.0% in LMM alone, and 13.0% in obesity with LMM (p for trend < 0.001). In a multivariable logistic regression analysis, the associations showed a positive trend for HHcy along the groups from obesity alone, to LMM alone, and to obesity with LMM. HHcy was independently associated with the presence of LMM alone (adjusted odds ratio 1.186 [95% confidence interval 1.117–1.259]) and obesity with LMM (1.424 [1.134–1.788]), respectively. This study demonstrated that HHcys was more strongly associated with coexistence of obesity and LMM than either condition alone in the adult population.

Obesity, waist circumference, and appendicular muscle mass ratio in relation to blood pressure among the community-dwelling elderly population in Taiwan

Hypertension is known to be related to obesity and both are the major factors for cardiovascular diseases. The relationship between body composition and blood pressure (BP) are discussed recently. Our study aims to evaluate the association between waist circumference (WC) and appendicular muscle mass (AMM) in relation to BP among the community‐dwelling elderly population.

Total 3739 patients (1600 males and 2139 females) were recruited in a series of community‐based surveys that were conducted among the elderly population in Taiwan from 2017 to 2019. We collected data on anthropometric characteristics, handgrip strength, and BP using standard methods. AMM was calculated with an equation. History of chronic disease and lifestyle profiles were collected using questionnaires.

The group with high AMM to body weight ratio (AMMW) showed lower systolic BP (SBP) (136.8 ± 19.1 to 140.6 ± 17.0 for males; 137.8 ± 18.3 to 142.7 ± 17.5 for females, both P < .001). Among central obese persons those with higher AMMW ratio had lower SBP. In the final model, AMMW in percentage is negatively associated to SBP (β = −0.641 in male, −0.780 in female, both P < .01). In other words, every 10% increase in AMMW is associated with decrease of SBP 6.41 mmHg in male and 7.80 mmHg in female.

Obesity and central obesity were positively associated with BP. The AMMW ratio was negatively associated with HTN and with a protective effect on BP even among the central obese. Health promotion programs to increase physical training may prevent hypertension among the elderly in Taiwan.

Nutritional Influences on Locomotive Syndrome

Healthy dietary habits are important to prevent locomotive syndrome (LS). We investigated the relationship between LS and nutritional intake using community health checkup data. We included 368 participants who underwent LS staging, blood sampling, and nutritional intake assessments. Participants (163 adults < 65: 205 older adults ≥ 65) were divided into normal (N; LS stage 0) and LS (L; LS stage 1–2) groups, and blood sample data and nutritional intake were compared between groups. Among adults (N group, 71; L group, 92), low-density lipoprotein cholesterol (LDL-C) was significantly lower, and Vitamin B₁ intake was significantly higher in the L than in the N group; LDL-C, p = 0.033; Vitamin B1, 0.029. Among older adults (N group, 85; L group, 120), hemoglobin (Hb), albumin, and calcium levels were significantly lower, and sodium, monounsaturated fatty acids (MUFA), and n-6 polyunsaturated fatty acids (n-6 PUFA) were significantly higher in the L than the N group; Hb, p = 0.036; albumin, 0.030; calcium, 0.025; sodium; 0.029; MUFA; 0.047, n-6 PUFA; 0.0233). Logistic regression analysis indicated that sodium was the risk factor for the L group (exp (B) 1.001, 95% CI: 1–1.001, p = 0.032). In conclusion, salt intake was associated with LS.

Aerobic Exercise Attenuates Pressure Overload-Induced Cardiac Dysfunction through Promoting Skeletal Muscle Microcirculation and Increasing Muscle Mass

Background

Aerobic exercise has been proven to have a positive effect on cardiac function after hypertension; however, the mechanism is not entirely clarified. Skeletal muscle mass and microcirculation are closely associated with blood pressure and cardiac function.

Objective

This study was designed to investigate the effects of aerobic exercise on the skeletal muscle capillary and muscle mass, to explore the possible mechanisms involved in exercise-induced mitigation of cardiac dysfunction in pressure overload mice.

Methods

In this study, 60 BALB/C mice aged 8 weeks were randomly divided into 3 groups: control (CON), TAC, and TAC plus exercise (TAE) group and utilized transverse aortic constriction (TAC) to establish hypertensive model; meanwhile, treadmill training is used for aerobic exercise. After 5 days of recovery, mice in the TAE group were subjected to 10-week aerobic exercise. Carotid pressure and cardiac function were examined before mice were executed by Millar catheter and ultrasound, respectively. Muscle mass of gastrocnemius was weighed; cross-sectional area and the number of capillaries of gastrocnemius were detected by HE and immunohistochemistry, respectively. The mRNA and protein levels of VEGF in skeletal muscle were determined by RT-PCR and western blot, respectively.

Results

We found that ① 10-week aerobic exercise counteracted hypertension and attenuated cardiac dysfunction in TAC-induced hypertensive mice; ② TAC decreased muscle mass of gastrocnemius and resulted in muscle atrophy, while 10-week aerobic exercise could reserve transverse aortic constriction-induced the decline of muscle mass and muscle atrophy; and ③ TAC reduced the number of capillaries and the protein level of VEGF in gastrocnemius, whereas 10-week aerobic exercise augmented the number of capillaries, the mRNA and protein levels of VEGF in mice were subjected to TAC surgery.

Conclusions

This study indicates that 10-week aerobic exercise might fulfill its blood pressure-lowering effect via improving skeletal muscle microcirculation and increasing muscle mass.

Dietary Protein Requirement Threshold and Micronutrients Profile in Healthy Older Women Based on Relative Skeletal Muscle Mass

Although multiple nutrients have shown protective effects with regard to preserving muscle function, the recommended amount of dietary protein and other nutrients profile on older adults for maintenance of high muscle mass is still debatable. The aims of this paper were to: (1) identify dietary differences between older women with low and high relative skeletal muscle mass, and (2) identify the minimal dietary protein intake associated with high relative skeletal muscle mass and test the threshold ability to determine an association with skeletal muscle phenotypes. Older women (n = 281; 70 ± 7 years, 65 ± 14 kg), with both low and high relative skeletal muscle mass groups, completed a food questionnaire. Skeletal muscle mass, fat-free mass (FFM), biceps brachii thickness, vastus lateralis anatomical cross-sectional area (VL_ACSA), handgrip strength (HGS), maximum elbow flexion torque (MVC_EF), maximum knee extension torque (MVC_KE), muscle quality (HGS/Body mass), and fat mass were measured. Older women with low relative skeletal muscle mass had a lower daily intake of protein, iodine, polyunsaturated fatty acid (PUFA), Vit E, manganese, milk, fish, nuts and seeds (p < 0.05) compared to women with high relative skeletal muscle mass. The minimum required dietary protein intake for high relative skeletal muscle mass was 1.17 g/kg body mass/day (g/kg/d) (sensitivity: 0.68; specificity: 0.62). Women consuming ≥1.17 g/kg/d had a lower BMI (B = -3.9, p < 0.001) and fat mass (B = -7.8, p < 0.001), and a higher muscle quality (B = 0.06, p < 0.001). The data indicate that to maintain muscle mass and function, older women should consume ≥1.17 g/kg/d dietary protein, through a varied diet including milk, fish and nuts that also contain polyunsaturated fatty acid (PUFA) and micronutrients such as iodine, Vit E and manganese.