Serum calcium and magnesium levels in acute gastroenteritis

Background: Acute diarrhea endemic in India has a prevalence of 7% which is commonly seen in children and also is a major problem in adults. Acute diarrhea with dehydration culminates in the loss of electrolytes. Not only Na + K + but also Ca 2+ and Mg 2+ are also substantially lost and lead to symptoms and adds to morbidity and prolong hospitalization. Methods: In this observational study, a total of 100 cases of acute gastroenteritis admitted to the department of general medicine and infectious disease ward of VIMSAR, Burla, between November 2018 to December 2019 were investigated clinically and biochemically and data were interpreted statistically. Results: Males (56%) were more in number than females (44%), were mostly in the age group of 26-35 years (24%). Hypocalcemia, hypokalemia, hypomagnesemia, and hyponatremia were found in 97%, 59%, 49%, 48% of cases respectively. Correlation of Serum Ca 2+ with (r-value) total episodes of vomiting (-0.536), total episode of stools (-0.880), S. Na + level (-0.374), S. K + level (-0.729), with the duration of hospital stay (-0.770) respectively. Correlation of S. Mg 2+ levels with (r-value) total episodes of vomiting (-0.475), total episode of stools (-0.498), S. Na + level (-0.301), S. K + level (-0.801), duration of hospital stay (-0.699) respectively. The correlations were found to be statistically highly significant (with a p-value is <0.01). Conclusion: Early detection and prompt correction of electrolytes will be beneficial, as it will decrease the duration of hospital stay, morbidity, mortality, thereby, decrease the burden on the health system of the country.


Introduction
Diarrhea is still a leading cause of mortality and morbidity over the world [1]. Acute diarrhea presents to primary health units are often managed with the goal for care of dehydration, prevention of the spread of infection, and empirical antibiotic in selected cases with fewer investigations done. Acute diarrhea can be attributed to viral, bacterial, and protozoan infection [2]. The peak age of presentation is although< 5 years many episodes of acute diarrhea with hospitalization with worse dyselectrolytemia is very common in elderly >60 years age group [1][2][3][4]. Acute diarrhea is defined as the passage of 3 or more loose stools in 24 hours. It is an endemic condition in India with a prevalence of 7% [1,5]. Electrolytes are lost in the diarrheal fluid, mainly Na+, K+, Cl-, HCO3-. Also, sodium and water reabsorption in the bowel is inhibited. Due to the loss of sodium and water in diarrhea, the body tries to retain sodium under the influence of aldosterone.

General objective
To study serum calcium and magnesium levels in acute gastroenteritis.  Regression analysis was done and r values were obtained statistical significance was declared if p<0.05.

Ethical issue:
The study was approved by the institutional ethics committee.

Results
In, the present study, out of 100 patients, 56% were male and 44% were female (Fig 1). Maximum patients were of the age group 26-35(24%) with an age range from a minimum of 17 years to maximum age of 80 years. The mean age was 42.14 ± 16.153 ( Fig-1).

Fig-2: Categorization according to the duration of hospital stay.
The minimum duration of hospital stay was 1 day to a maximum of 6 days with a mean of 2.3 days±1.494. The majority of the patients stayed for 1 day (Fig-2).  Total cases with a value of ≤135 mmol/l were 48% (Fig-5). The values of serum potassium documented were a minimum of 1.5 mmol/l to a maximum of 5 mmol/l with a mean of 3.366 mmol/l±0.6.6726. The majority of cases were in the range of 2.6-3.5 mmol/l (36%). Total cases with a value of serum potassium ≤3.5 mmol/l were 59% (Fig-6). The range of serum calcium obtained was 6.7 to 9.8 mmol/l (mean 8.223mmol/L±0.5590). The majority of cases were in the range of 8.1-8.5 mmol/l (57%) followed by 21 cases of serum Calcium value within 6.7-8 mmol/l (Fig-7). About the levels of serum magnesium, the range obtained was 1.1 to 2.9 mg/dl (mean1.710 mg/dl±0.3935). The majority of cases were in the range of 1.7-1.9 mg/dl (35%).
Total cases with value of serum magnesium<1.7 mg/dl were (49%) (Fig-8).  (Table-1).   In the present study, hypokalaemia was seen in 59% of the study population. The minimum serum potassium level was 1.5 mmol/L and the maximum was 5.1 mmol/L with a mean of 3.37±0.98. mmol/L. The majority of the population (36%) had hypokalaemia with serum potassium lying between 2.6 to 3.5 mmol/L followed by 1.5 to 2.5 mmol/L (23%) compared to Patel et al [9] were 39% cases had hypokalaemia on admission and 22% cases had severe hypokalaemia higher than 23% of study by Anjali et al [8].
The correlation of serum calcium levels with total episodes of vomiting has a Pearson coefficient, r value -0.536 with a p-value < 0.05. The serum calcium level is inversely proportional to total episodes of vomiting; which was found to be statistically significant. The correlation of serum calcium levels with total episodes of stools has a Pearson coefficient, r value -0.880 with a p-value < 0.05, the serum calcium level is inversely proportional to total episodes of stools; which was also found to be statistically significant. The changes in serum calcium level have a stronger association with total episodes of stools than that of vomiting.
The correlation of serum calcium levels with serum sodium level has a Pearson coefficient, r value 0.374 with a p-value < 0.05. The serum calcium level is directly proportional to serum sodium level; which was found to be statistically significant. The correlation of serum calcium levels with serum potassium level has a Pearson coefficient, r value 0.729 with a p-value < 0.05. The serum calcium level is directly proportional to serum potassium level; which was found to be statistically significant. The changes in serum calcium level have a stronger association with serum potassium level than serum sodium level.
In this study, the correlation of serum calcium levels with the duration of hospital stay has a Pearson coefficient, r value -0.770 with a p-value < 0.05. The serum calcium level is inversely proportional to the duration of hospital stay; which was found to be statistically significant. The correlation of serum magnesium levels with total episodes of vomiting has a Pearson coefficient, r value -0.475 with a pvalue < 0.05. The serum magnesium level is inversely proportional to total episodes of vomiting; which was found to be statistically significant. The correlation of serum magnesium levels with total episodes of stools has a Pearson coefficient, r value -0.498 with a p-value < 0.05, the serum magnesium level is inversely proportional to total episodes of stools; which was found to be statistically significant. The changes in serum magnesium level have a stronger association with total episodes of stools than that of vomiting.
In the present study, the correlation of serum magnesium levels with serum sodium level has a Pearson coefficient, r value 0.301 with a p-value < 0.05. The serum magnesium level is directly proportional to serum sodium level; which was found to be statistically significant. The correlation of serum magnesium levels with serum potassium level has a Pearson coefficient, r value 0.801 with a p-value < 0.05, the serum magnesium level is directly proportional to serum potassium level; which was found to be statistically significant. The changes in serum magnesium level have a stronger association with serum potassium level than serum sodium levels.
The correlation of serum magnesium levels with a duration of hospital stay has Pearson coefficient, r value -0.699 with a p-value < 0.05. The serum magnesium level is inversely proportional to the duration of hospital stay; which was found to be statistically significant. The correlations described above have never been earlier studied in the adult population in patients of acute gastroenteritis.

Limitations
The sample size was only 100. So, it may not have been represented by the target population. Electrolyte estimation was done only on admission.
A comparative data on admission versus on discharge would throw light on how the treatment influences the electrolyte imbalance it would also point out the limitations of conventional treatment protocols.
Secondly, stool levels of Mg2+, K+, Ca2+, and urinary Mg2+, K+ levels could not be measured to document the loss of Mg 2+ and Ca2+ in stool and Mg2+ and K+ loss in urine due to non-availability of these investigations at our set up.

Conclusion
In the present study, hypocalcemia (97%), hypokalemia (59%), hypomagnesemia (49%), and hyponatremia (48%) were reported. Therefore, serum electrolytes such as calcium, magnesium should also be investigated along with routine serum sodium and potassium. Early detection and prompt correction of electrolytes will be beneficial as it will decrease the duration of hospital stay, morbidity, the mortality of patients and will decrease the burden on the health system of the country.
What does the study add to the existing knowledge?
Also, adequate measures should be taken for the prevention and control of acute gastroenteritis.
Still large multicentric study with larger populations, avoiding limitations will ensure stronger evidence and strong recommendations concerning the management of acute diarrhea with dehydration and dyselectrolytenemia.