Introduction:
Hyponatremia is the most common electrolyte disorder in clinical medicine and can be encountered in a variety of diseases. The term ‘asymptomatic hyponatremia’ is frequently used in clinical settings. Symptoms of mild or moderate hyponatremia (<125-135 mmol/L) are rather non-descript, these patients do not present with any overt symptoms, therefore maybe commonly missed in routine practice. Sodium is known to be associated in regulation of many homeostatic mechanisms in our body, thus slight alteration may hamper the general wellbeing.
Methods:
This study is a single center hospital based observational case-control study conducted in a tertiary care center in Eastern India (IPGMER & SSKM HOSPITAL) for a period of 18 months (September 2021-February 2023). A total of 75 patients with CKD stages II-IV with and without hyponatremia were included. Data collected was analyzed using SPSS version 26. Independent samples T-tests was computed for all recorded variables of BAMSE score, ADL scores, DEXA scans, inflammatory biomarkers, and biochemical data between groups of “normonatremia” and “asymptomatic hyponatremia”. Differences in demographic and clinical characteristics between cases and controls were evaluated using univariate linear regression models. A multivariable linear regression model was used to examine associations between BMD and hyponatremia, controlling for comorbidities and diuretics. Results were expressed as ‘t’ values with 95% confidence intervals (CIs).
Results:
Mean age of the study population was 42.36±31.936 years.56.7% were males and 43.3% were females. 67.6% of the cases and 73.7% of the controls were hypertensive. 24.3% of the cases and 13.1% of the controls were diabetic. 24.3% of the cases and 15.8% of the controls had a history of coronary artery disease.
Comparison of serum sodium levels with CRP levels using univariate linear regression showed inverse correlation which was statistically significant (p=0.001). Serum sodium levels and IL-6 also showed a inverse correlation. Serum sodium and DEXA (T scores) showed a positive correlation. All the above correlations were statistically significant.
In a multinomial linear regression model; BMI, CRP, IL-6 showed a statistically significant result with serum sodium levels with coefficients being 0.235, -0.428 and -0.308. BMI showed a positive correlation whereas CRP and IL-6 levels showed a negative correlation with serum sodium levels. Rest BAMSE (Bangla Adapted Mental status examination), ADL (Activities of Daily living) scores, eGFR and NTproBNP all showed a positive correlation but the association was not significant.
Conclusions:
In our study we found an association between osteopenia or osteoporosis and mild hyponatremia in non-dialysis dependent CKD patients. This could have an implication on the treatment of osteoporosis. We found a strong negative correlation between serum sodium and inflammatory markers like CRP and IL-6 which indicates inflammation but causal association cannot be analyzed in this study. Further studies with proper adjustment of confounding factors are required to establish causation and its implication on treatment of mild asymptomatic hyponatremia.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.