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.

Revisiting the association of blood pressure with mortality in oldest old people in China: community based, longitudinal prospective study.

OBJECTIVE: To examine the associations of blood pressure with all cause mortality and cause specific mortality at three years among oldest old people in China. DESIGN: Community based, longitudinal prospective study. SETTING: 2011 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey, conducted in 22 Chinese provinces. PARTICIPANTS: 4658 oldest old individuals (mean age 92.1 years). MAIN OUTCOME MEASURES: All cause mortality and cause specific mortality assessed at three year follow-up. RESULTS: 1997 deaths were recorded at three year follow-up. U shaped associations of mortality with systolic blood pressure, mean arterial pressure, and pulse pressure were identified; values of 143.5 mm Hg, 101 mm Hg, and 66 mm Hg conferred the minimum mortality risk, respectively. After adjustment for covariates, the U shaped association remained only for systolic blood pressure (minimum mortality risk at 129 mm Hg). Compared with a systolic blood pressure value of 129 mm Hg, risk of all cause mortality decreased for values lower than 107 mm Hg (from 1.47 (95% confidence interval 1.01 to 2.17) to 1.08 (1.01 to 1.17)), and increased for values greater than 154 mm Hg (from 1.08 (1.01 to 1.17) to 1.27 (1.02 to 1.58)). In the cause specific analysis, compared with a middle range of systolic blood pressure (107-154 mm Hg), higher values (>154 mm Hg) were associated with a higher risk of cardiovascular mortality (adjusted hazard ratio 1.51 (95% confidence interval 1.12 to 2.02)); lower values (<107 mm Hg) were associated with a higher risk of non-cardiovascular mortality (1.58 (1.26 to 1.98)). The U shaped associations remained in sensitivity and subgroup analyses. CONCLUSIONS: This study indicates a U shaped association between systolic blood pressure and all cause mortality at three years among oldest old people in China. This association could be explained by the finding that higher systolic blood pressure predicted a higher risk of death from cardiovascular disease, and that lower systolic blood pressure predicted a higher risk of death from non-cardiovascular causes. These results emphasise the importance of revisiting blood pressure management or establishing specific guidelines for management among oldest old individuals.

[Construction and biological assessment of tissue engineering intervertebral disc].

OBJECTIVE: To investigate the value of bone marrow-mesenchymal stem cells (BM-MSCs) transformed by nucleus pulposus (NPs) for construction of tissue engineering disc. METHODS: BM-MSCs and fetal NPs were cultured in vitro, planted on polylactic acid-polyglycolic acid copolymer (PLGA), and observed with inverted microscope and scanning electronic microscope. PLGA scaffolds with adherent BM-MSCs and NPs, as well as BM-MSCs and NPs suspension were implanted into intervertebral discs of New Zealand white rabbits, respectively. Intervertebral signal intensity was evaluated by Thompson grading 12 weeks later. Proteoglycan and type IIcollagen were determined by spectrophotometric method and immunohistochemistry, respectively. RESULTS: Spindle or multi-angular BM-MSCs turned into fibro-like phenotype coculture of BM-MSCs and NPs, which grew well with normal morphology when they attached on PLGA scaffolds. There was statistical difference in intervertebral signal intensity, and the expression of proteoglycan and type IIcollagen between PLGA scaffolds group and control group (P < 0.05), the content of proteoglycan was (3.93 ± 0.31) mg/100 mg in the PLGA scaffolds group whereas (3.52 ± 0.26) mg/100 mg in the control group. CONCLUSIONS: BM-MSCs can be induced into NPs by cocultivation, and PLGA scaffolds can provide good growing conditions, and maintain high mechanical properties and spacial structure which meet the requirement of tissue engineering disc to prevent degeneration.