Association Of Serum Cystatin C With Functional Disability And Depressive Symptoms Among Elderly People

At present,the global population has gradually entered the stage of aging.The protection of the physical and mental health of the elderly has long been a problem that the public needs to solve urgently.Daily behavioral and emotional disorders are common in the elderly and have a direct negative impact on the lives of older people,placing a great burden on families and society.Impaired renal function is a chronic disease that is more common in the elderly.The adverse outcomes of kidney disease often cause declines in the elderly's behavior and:depressive symptoms.The serum concentration of cystatin C in the blood is not easily affected by,age,sex,muscle mass,and diet.It is currently used as an endogenous marker of renal damage and can be used to indicate early acute or chronic renal function.damage.Recent studies have shown that serum cystatin C is associated with several aging-related diseases,and cystatin C is often elevated in patients with cardiovascular and cerebrovascular diseases and chronic inflammation.However,the relationship between cystatin C and cystatin C-based impaired renal function and functional disability and depressive symptoms in the elderly remains unclear.ObjectiveTo explore the relationship between serum cystatin C and cystatin C-based renal dysfunction and physical and mental health of the elderly,that is,functional disability and depressive symptoms,which might facilitate early prevention and intervention to reduce functional disability and depressive symptoms in the elderly.Materials and methods1.Study subjectsThe basic design of this study refers to as the population-based longitudinal study in a rural community.A total of 1743 elderly people aged 60 years or older living in the Xinglongzhuang Coal Mine Community 20 km away from Qufu,Jining,Shandong Province were selected as the study objects.303 people who had not collected important data due to refusal to join or fail to cooperate were excluded.At baseline(2010-2011),we conducted a cross-sectional survey of the remaining 1440 elderly people.In 2014-2016,follow-up surveys were conducted on 828 participants who also participated in the baseline survey.2.Data collectionThe survey questionnaire was used to collect general information,relevant biochemical indicators,and chronic disease history of the study population.Estimated of GFR was calculated and impaired renal function was defined as eGFR<60 ml/min/1.73 m2.The Katz BADL and Lawton's IADL were used to assess the status of behavioral function,and the GDS-15 was used to assess depression status.3.Statistical analysisThe study population was grouped according to presence or absence of functional disability and depressive symptoms.SPSS 22.0 was used to analyze the data by T-test,Chi-square test,Pearson or Spearman correlation test,and multivariate logistic regression.Follow-up data were analyzed using the Cox survival analysis.Results1.The incidence of functional disability of the elderly in the community was 17.3%,The cystatin C level in the functional disability group was significantly higher than that in the non-functional disability group(p<0.01).Higher levels of cystatin C(1.01-1.25,>1.25mg/L)and impaired renal function were independent risk factors for functional disability(OR=1.77,OR=1.70,OR=1.45).2.In the baseline data,the proportion of depressive symptoms was 21.9%.Compared with the group without depression,the level of cystatin C in the depressive symptoms group was significantly higher(p<0.01).Higher levels of cystatin C(1.01-1.25,>1.25mg/L)and impaired renal function were independent risk factors for depressive symptoms(OR=1.57,OR=4.09,OR=3.02).3.Of the 828 participants who were followed,669 had no depressive symptoms at baseline.After an average of 3.6 years of follow-up,157 patients developed new depressive symptoms.Cox analysis showed that higher levels of Cys C(>1.25 mg/L)and impaired renal function were independent risk factors for depressive symptoms(HR=2.36,HR=1.59).ConclusionThe level of serum cystatin C is related to the risk of behavioral dependence and depressive symptoms in the elderly.Concerned about serum cystatin C levels may be helpful for the protection of elderly people's physical and mental health.