Correlations of spot urinary sodium and potassium with blood pressure in pregnant women: A longitudinal study in Southern Thailand.

OBJECTIVE: To assess the changes of spot urinary sodium and potassium and blood pressure (BP) throughout pregnancy and their correlations in southern Thailand. METHODS: A longitudinal study was conducted in southern Thailand from March 2018 to November 2019. Spot urinary excretion of sodium per creatinine (U[Na+ ]/[Cr]), potassium per creatinine (U[K+ ]/[Cr]) and U[Na+ ]/[K+ ] ratios, and BP were measured at four time points throughout pregnancy. A one-way analysis of variance with repeated measures and Bonferroni correction with post hoc analysis was used to identify significant differences between time points. The correlations were measured using Pearson's correlation coefficients. RESULTS: A total of 327 pregnant women were included. Both systolic and diastolic BPs decreased gradually from up to 14 weeks of pregnancy to 18-22 weeks and then increased until 30-34 weeks. Mean spot U[Na+ ]/[Cr] ratios did not significantly change during the study period. Mean spot U[K+ ]/[Cr] ratios gradually increased, and spot U[Na+ ]/[K+ ] ratios gradually decreased. The correlation of spot U[Na+ ]/[Cr] and U[K+ ]/[Cr] ratios with BPs was weakly negative at all four time points. CONCLUSIONS: Spot U[Na+ ]/[Cr] and U[K+ ]/[Cr] ratios are inversely correlated with BPs; weak correlations are found among pregnant women in southern Thailand. Further research in different populations is required to confirm its correlation and broader use.

Loss of high density lipoprotein cholesterol in serum: effect of storage.

UNLABELLED: The objectives of the study were to determine the magnitude and pattern of loss of detectable high density lipoprotein cholesterol (HDL-C) as functions of time and temperature of storage. Serum from 29 consented adults were estimated for HDL-C (utilising polyethylene glycol and alpha-cyclodextrin) when freshly obtained and after storage at 4 degrees C, -20 degrees C and - 70 degrees C at varied intervals up to a maximum of 120 days. The concentration of fresh HDL-C ranged from 16.9 to 87.2 mg/dl. After 5 days of storing at 4 degrees C, an average of 5% of HDL-C could not be detected. After 120 days of storing at -20 degrees C, 6-8 mg/dl of HDL-C was 'lost, this represented 10-20% of the concentration of the fresh samples. Storage at -70 degrees C resulted in a 'loss' of 3%. The pattern of reduction of detectable HDL-C was such that the initial loss (first few days) was very rapid, reaching a nadir in 20 days. Examining individual serum samples, the loss ranged from minimal up to 30% of the original concentrations for all condition of storage. From further analysis of some portion of the data, there were suggestions that the concentration of triglyceride could be affect the loss of HDL-C with storage. CONCLUSION: Such rate of loss and heterogeneity of loss of detectable HDL-C, so far unexplained, may have implications in the management of epidemiological surveys involving storage of lipids in tropical countries.