Associations of Sarcopenia, Handgrip Strength and Calf Circumference with Cognitive Impairment among Chinese Older Adults

Objective To evaluate the associations of sarcopenia,handgrip strength and calf circumference with cognitive impairment among Chinese older adults.Methods Totally 2,525 older adults were recruited from the Healthy Aging and Biomarkers Cohort Study.Cognitive impairment was assessed by the Chinese Mini-Mental State Examination.Handgrip strength was calculated from the means of the right and left hand values.Calf circumference was measured at the site of maximum circumference of the non-dominant leg.The formula developed by Ishii was used to define sarcopenia.Multiple logistic regression was performed to evaluate the associations of sarcopenia,handgrip strength,and calf circumference with cognitive impairment.Results The prevalence of cognitive impairment was 34.36%.The adjusted odds ratio(OR)for cognitive impairment in individuals with sarcopenia was 2.55[95% confidence interval(95%CI):1.86-3.50].Compared with individuals in the first quartile(Q1)of calf circumference,the adjusted ORs in the second,third,and fourth quartiles(Q_(2),Q_(3),and Q_(4))were 0.75(95% CI:0.58-0.96),0.59(95% CI:0.44-0.79),and 0.62(95% CI:0.45-0.8),respectively.Compared with individuals in Q1 of handgrip strength,the adjusted ORs for Q_(2),Q_(3),and Q_(4) were 0.49(95%CI:0.38-0.62),0.31(95% CI:0.23-0.41),and 0.30(95%CI:0.21-0.44),respectively.Conclusion Sarcopenia,identified by low handgrip strength and low calf circumference,was positively associated with cognitive impairment.

Urinary Creatinine Concentrations and Its Explanatory Variables in General Chinese Population:Implications for Creatinine Limits and Creatinine Adjustment

Objective The study aimed to analyze the applicability of the World Health Organization’s exclusionary guidelines for Urinary creatinine(Ucr)in the general Chinese population,and to identify Ucr related factors.Methods We conduct a cross-sectional study using baseline data from 21,167 participants in the China National Human Biomonitoring Program.Mixed linear models and restricted cubic splines(RCS)were used to analyze the associations between explanatory variables and Ucr concentration.Results The geometric mean and median concentrations of Ucr in the general Chinese population were 0.90 g/L and 1.01 g/L,respectively.And 9.36%samples were outside 0.3-3.0 g/L,including 7.83%below the lower limit and 1.53%above the upper limit.Middle age,male,obesity,smoking,higher frequency of red meat consumption and chronic kidney disease were associated significantly with higher concentrations of Ucr.Results of the RCS showed Ucr was positively and linearly associated with body mass index,inversely and linearly associated with systolic blood pressure,diastolic blood pressure,triglycerides level,and glomerular filtration rate,and were non-linearly associated with triiodothyronine.Conclusion The age-and gender-specific cut-off values of Ucr that determine the validity of urine samples in the general Chinese population were recommended.To avoid introducing bias into epidemiologic associations,the potential predictors of Ucr observed in the current study should be considered when using Ucr to adjust for variations in urine dilution.

Carbon carry capacity and carbon sequestration potential in China based on an integrated analysis of mature forest biomass

Forests play an important role in acting as a carbon sink of terrestrial ecosystem.Although global forests have huge carbon carrying capacity(CCC)and carbon sequestration potential(CSP),there were few quantification reports on Chinese forests.We collected and compiled a forest biomass dataset of China,a total of 5841 sites,based on forest inventory and literature search results.From the dataset we extracted 338 sites with forests aged over 80 years,a threshold for defining mature forest,to establish the mature forest biomass dataset.After analyzing the spatial pattern of the carbon density of Chinese mature forests and its controlling factors,we used carbon density of mature forests as the reference level,and conservatively estimated the CCC of the forests in China by interpolation methods of Regression Kriging,Inverse Distance Weighted and Partial Thin Plate Smoothing Spline.Combining with the sixth National Forest Resources Inventory,we also estimated the forest CSP.The results revealed positive relationships between carbon density of mature forests and temperature,precipitation and stand age,and the horizontal and elevational patterns of carbon density of mature forests can be well predicted by temperature and precipitation.The total CCC and CSP of the existing forests are 19.87 and 13.86 Pg C,respectively.Subtropical forests would have more CCC and CSP than other biomes.Consequently,relying on forests to uptake carbon by decreasing disturbance on forests would be an alternative approach for mitigating greenhouse gas concentration effects besides afforestation and reforestation.