Dietary protein intake and changes in muscle mass measurements in community-dwelling middle-aged and older adults: A prospective cohort study

BACKGROUND & AIMS

Increasing dietary protein intake can be an efficient strategy to prevent sarcopenia. Nevertheless, due to the discrepancy in the population and their dietary pattern, evidence suggested the effects of dietary protein amount or source on sarcopenia prevention varies. This prospective cohort study investigated the correlation between dietary protein intakes or sources and changes in muscle mass measurements. Additionally, the study explored the link between dietary protein and the prevalence of sarcopenia.

METHODS

Participants aged 40 to 75 were from Guangzhou Nutrition and Health Study (GNHS) 2011-2013 and returned in 2014-2017. Validated 79-item food frequency questionnaires were applied to calculate the amount of total, animal, and plant protein intakes and animal-to-plant protein ratio (APR). The body composition was examined by dual-energy x-ray absorptiometry (DXA) to calculate the appendicular lean mass (ALM) and its index (ASMI). Sarcopenia was diagnosed based on the 2019 Asia Working Group of Sarcopenia's criteria. ANCOVA was utilized to compare the differences of Δ ALM and Δ ASMI across the quartiles of the dietary protein, and linear regression was employed to examine dose-response associations. Multilinear mixed-effect models were employed to evaluate whether protein intake relates to annual changes in ALM and ASMI. Multivariable logistic regressions were performed to analyze the associations between dietary protein and sarcopenia.

RESULTS

In total, 2709 participants during the 3.2-year follow-up period were considered eligible for analysis. Higher dietary protein intakes (total, animal, plant) in both sexes could preserve more ALM and ASMI in a dose-response manner (all P-trend < 0.05). The annual estimated preservations of ASMI were greater in the highest dietary protein intakes (total, animal, plant) quartile than the lowest (0.05-0.13 kg/m2/y, all P < 0.05). In women, the risk of sarcopenia was reduced by 35%-50 % in the highest protein intake (total, animal, plant) quartile than the lowest. The APR did not display any significant associations.

CONCLUSIONS

Higher dietary protein intake, regardless of animal or plant sources, is associated with less muscle loss and a lower prevalence of sarcopenia in middle-aged and older Chinese, particularly women.

CLINICALTRIALS

GOV IDENTIFIER

NCT03179657.

Appendicular Skeletal Muscle Mass Index Level (ASMI) and Its Influencing Factors in Healthy Adult Males

Background

We aimed to retrospectively analyze the level of appendicular skeletal muscle mass index (ASMI) in adult males and its influencing factors for early screening and intervention of sarcopenia.

Methods

From January 2020 to December 2021, adult male medical examiners from the Health Management Center of the Affiliated Hospital of North Sichuan Medical College, Chengdu City, China were selected as the research subjects. The ASMI level was measured by bioelectrical impedance (BIA) method. The subjects were divided into four groups according to the quartiles of ASMI level, the levels of related indicators between the groups were compared, and the related factors affecting the ASMI level were analyzed.

Results

The detection rate of sarcopenia was about 1.09% (78/7187). One-way ANOVA or nonparametric test results showed that age, BMI, WHR, SBP, DBP, FPG, HbA1c, AST, ALT, GGT, Cr, UA, TG, TC, HDLC, LDL-C and FT3 levels were significantly different among the four ASMI groups (P<0.05). ASMI was positively correlated with BMI, WHR, SBP, DBP, FPG, HbA1c, AST, ALT, GGT, Cr, UA, TG, TC, LDL-C, FT3, and TSH (all P<0.05); negatively correlated with age and HDL-C (all P<0.05). Age, WHR and TG were independent risk factors for ASMI level, and BMI was an independent protective factor for ASMI level.

Conclusion

The ASMI level in healthy adult males is related to age, obesity, blood pressure, glucose and lipid metabolism disorder, inflammation and thyroid hormone, among which age, BMI, WHR and TG are independent influencing factors of ASMI level.

A nomogram for screening sarcopenia in Chinese type 2 diabetes mellitus patients

OBJECTIVE

Diabetes is an important risk factor for sarcopenia and contributes to poor prognosis; it is important for clinicians to identify sarcopenia early in the population with type 2 diabetes mellitus. Our aim was to establish a clinical screening model of sarcopenia in Chinese patients with type 2 diabetes mellitus.

METHODS

A cross-sectional study was conducted involving 1131 hospitalized patients (62.67 ± 11.25 years) with type 2 diabetes mellitus, including 560 men and 571 women. All muscle/fat parameters were measured by dual energy X-ray absorptiometry and the clinical correlation with sarcopenia was evaluated. The least absolute shrinkage and selection operator was used to select optimal variables and build a nomogram chart of the sarcopenic screening model for patients with type 2 diabetes mellitus, respectively. The area under the receiver operating characteristic curve (AUC), the calibration curve, the analysis of the decision curve, the clinical impact curve, and external validations were used to evaluate discriminative ability and clinical applicability.

RESULTS

The prevalence of sarcopenia in patients with type 2 diabetes mellitus was 30.06 % (340/1131). Compared to the non-sarcopenic group, the sarcopenic group was older, more likely to be men, and had a higher heart rate and lower body mass index (BMI), waist-hip ratio (WHR), upper limb muscle mass, lower limb muscle mass and fat paraments (all P < 0.05). Five independent variables (age, sex, BMI, WHR and heart rate) were selected to construct a nomogram prediction model. The AUC was 0.907 (95 % CI: 0.890-0.925). The calibration curve, decision curve analysis, and clinical impact curves showed a wide range of nomograms with good clinical applicability under threshold probability. Additionally, internal validation showed a good AUC of 0.908 (95 % CI: 0.886-0.928) in the training set and 0.904 (95 % CI: 0.868-0.941) in the testing set, as well as an accuracy of 93.2 % for the screening of sarcopenia in the external validation set.

CONCLUSIONS

Age, sex, BMI, WHR, and heart rate were used to detect sarcopenia in patients with type 2 diabetes mellitus. The novel screening model is an accurate, easy-to-implement and low-cost tool for early identification of sarcopenia in Chinese patients with type 2 diabetes mellitus.

Correlation between parameters related to sarcopenia and gray matter volume in patients with mild to moderate Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease characterized by brain atrophy and closely correlated with sarcopenia. Mounting studies indicate that parameters related to sarcopenia are associated with AD, but some results show inconsistent. Furthermore, the association between the parameters related to sarcopenia and gray matter volume (GMV) has rarely been explored.

AIM

To investigate the correlation between parameters related to sarcopenia and cerebral GMV in AD.

METHODS

Demographics, neuropsychological tests, parameters related to sarcopenia, and magnetic resonance imaging (MRI) scans were collected from 42 patients with AD and 40 normal controls (NC). Parameters related to sarcopenia include appendicular skeletal muscle mass index (ASMI), grip strength, 5-times sit-to-stand (5-STS) time and 6-m gait speed. The GMV of each cerebral region of interest (ROI) and the intracranial volume were calculated by computing the numbers of the voxels in the specific region based on MRI data. Partial correlation and multivariate stepwise linear regression analysis explored the correlation between different inter-group GMV ratios in ROIs and parameters related to sarcopenia, adjusting for covariates.

RESULTS

The 82 participants included 40 NC aged 70.13 ± 5.94 years, 24 mild AD patients aged 73.54 ± 8.27 years and 18 moderate AD patients aged 71.67 ± 9.39 years. Multivariate stepwise linear regression showed that 5-STS time and gait speed were correlated with bilateral hippocampus volume ratios in total AD. Grip strength was associated with the GMV ratio of the left middle frontal gyrus in mild AD and the GMV ratios of the right superior temporal gyrus and right hippocampus in moderate AD. However, ASMI did not have a relationship to any cerebral GMV ratio.

CONCLUSIONS

Among parameters related to sarcopenia, 5-STS time and gait speed were associated with bilateral hippocampus volume ratios at different clinical stages of patients with AD. Five-STS time provide an objective basis for early screening and can help diagnose patients with AD.

Association between appendicular skeletal muscle index and leukocyte telomere length in adults: A study from National Health and Nutrition Examination Survey (NHANES) 1999-2002

BACKGROUND

A higher body mass index (BMI) is associated with shorter telomeres. The loss of muscle mass with aging is associated with adverse outcomes. The appendicular skeletal muscle index (ASMI) is currently used to quantify muscle mass.

OBJECTIVE

We investigated the association of the ASMI with leukocyte telomere length in adult Americans.

METHODS

This cross-sectional study used the National Health and Nutrition Examination Survey (NHANES) 1999-2002 dataset. Body composition was measured by dual-energy X-ray absorptiometry. Low muscle mass was defined using sex-specific thresholds of the appendicular skeletal muscle mass index (ASMI). The telomere-to-single-copy gene ratio (T/S ratio) was converted to base pairs. Generalized linear models were performed to evaluate the association of ASMI with telomere length.

RESULTS

In multivariable adjustment regression models, higher ASMI was associated with longer telomeres in US adults (β = 70.2, P < 0.001, P trend<0.001). In participants with preserved muscle mass, the ASMI was related to longer telomere length (β = 75.1, P < 0.001), but not significantly in low muscle mass participants (β = 68.7, P = 0.30). Further subgroup analysis by a combination of age groups and muscle mass status showed positive association with young-preserved muscle mass (β = 82.6, P < 0.001), old-preserved muscle mass (β = 44.4, P = 0.12), young-low muscle mass (β = 135.4, P = 0.20), and old-low muscle mass (β = 52.7, P = 0.55). Because each additional year of chronological age was associated with telomeres that were 15.3 base pairs shorter, on average, this would equate to 5.4 fewer years of biological aging (82.6 ÷ 15.3) in the young-preserved muscle mass participants.

CONCLUSIONS

A higher ASMI is associated with longer telomeres. The prevention of skeletal muscle loss has the potential to delay telomere shortening and account for less biological aging.

[Risk factors of cirrhosis combined with sarcopenia and their impact on clinical outcomes]

Objective: To study the occurrence of sarcopenia in patients with liver cirrhosis, and to explore their risk factors and impact on clinical outcomes. Methods: 199 hospitalized cases with liver cirrhosis were collected for nutritional risk screening, anthropometric measurement and blood biochemical examination. The body composition analysis was measured based on the skeletal muscle content of the four limbs to calculate the appendicular skeletal muscle mass index (ASMI). Patients were divided into sarcopenia and non-sarcopenia group and the relevant indexes of both groups were compared to screen for factors affecting the occurrence of sarcopenia. During the follow-up of 48 months, the survival and complications of the both groups were compared. Statistical analysis was performed using t-test, χ(2) test and logistic regression analysis in terms of different data. Results: The incidence of sarcopenia in cirrhosis was 36.7%, with the highest prevalence in patients with recurrent hepatic encephalopathy (62.5%), followed by patients with abdominal ascites / pleural effusion (37.6%). The incidence of sarcopenia was significantly higher in those with nutritional risk than in those without nutritional risk (P < 0.05). However, even among those without nutritional risk, 14.8% had combined sarcopenia. The body mass index (BMI), upper arm muscle circumference (AMC), and body cell mass (BCM) of the sarcopenia group were lower than those of the non-sarcopenia group (P < 0.05), and the edema index (ECW/TBW) was higher than the latter (P < 0.05). Multivariate analysis showed that age, gender, BMI, and complications of hepatic encephalopathy were the main influencing factors of cirrhosis combined with sarcopenia (P < 0.05). During the follow-up period, the sarcopenia group had a higher mortality rate than non-sarcopenia goup (P < 0.05), and the incidence of recurrent abdominal ascites/pleural effusion, hepatic encephalopathy, and infection was also significantly elevated (P < 0.05). Conclusion: Sarcopenia is one of the manifestations of malnutrition in patients with liver cirrhosis, which increases the risk of mortality and other complications, and has adverse impact on the clinical outcome. Additionally, older age, male sex, low BMI and recurrent hepatic encephalopathy has higher risk for developing sarcopenia.