Analysis Of The Etiology And Clinical Characteristics Of Hypokalemia-with 4 Cases Of Bartter Syndrome In Adults

Objective:In this study,the etiology and clinical characteristics of hypokalemia in the Endocrinology Department of our hospital in the past 2 years were analyzed.We also analyzed the clinic data of adult BS which diagnosed by gene detection,to provide a reference for the etiological diagnosis of hypokalemia.Methods:We retrospectively analyzed the clinical data of patients with hypokalemia in the Endocrinology Department of our hospital from January 1,2021 to December 31,2022.We collected gender,age,underlying diseases,clinical manifestations,blood pressure,blood biochemistry,to analyze the etiology and clinical characteristics of hypokalemia.Meanwhile,the data of clinical cases after genetic testing were analyzed,and the clinical characteristics of 4 adult BS cases were analyzed in combination with literature.Results:There were 442 cases of hypokalemia admitted to:1.There were 237 cases（53.62%）in males and 205 cases（46.38%）in females,and the ratio of male to female was 1.16:1.2.The age ranged from 14 to 92 years old,with a median of 55 years old,104cases（23.53%）were under 40 years old,183 cases（41.40%）were between 40 and 60years old,and 155 cases（35.07%）were over 60 years old.3.There were 319 cases（72.17%）with mild hypokalemia,106 cases（23.98%）with moderate hypokalemia,17 cases（3.85%）with severe hypokalemia.Among them,the proportion of patients with severe hypokalemia in each age group gradually decreased with age,and the difference was statistically significant（P<0.05）,but there was no statistical significance in the distribution of patients with mild and moderate hypokalemia in different age groups（P>0.05）.4.There was no statistical significance in gender,systolic blood pressure,diastolic blood pressure,ALT,AST,TBIL,DBIL,ALB,FBG,Scr,TC,TG,HDL-C,LDL-C,Na⁺,Ca²⁺,Mg²⁺between different degrees of hypokalemia（P>0.05）.With the increase of the degree of hypokalemia,Cl^-decreased gradually,and the difference was statistically significant（P<0.05）.5.There were 232 cases（52.49%）of diabetes-related hypokalemia,39 cases（8.82%）of insufficient intake,38 cases（8.60%）of digestive tract loss,37 cases（8.37%）of hyperthyroidism,32 cases（7.24%）of unexplained hypokalemia,30cases（6.79%）of aldosteronism,17 cases（3.85%）of drug-induced hypokalemia,4cases（0.90%）of BS,3 cases（0.68%）of renal tubular acidosis,2 cases（0.45%）each in Sjogren’s syndrome,Cushing’s syndrome and respiratory alkalosis,1 case each（0.23%）in hypokalemic periodic paralysis type 2,pheochromocytoma,17α-hydroxylase deficiency,and familial hyperaldosteronism type 3.6.Hypokalemia caused by diabetes,insufficient intake,digestive tract loss,hyperthyroidism,and aldosteronism were mainly mild.7.Sixteen patients completed genetic testing,of which 4 patients were diagnosed as adult BS,3 patients were diagnosed as hypokalemic periodic paralysis type 2,familial hyperaldosteronism type 3 and 17α-hydroxylase deficiency respectively.8.Four cases of adult BS showed hypokalemia,metabolic alkalosis,hypocalciuria,hyperkaluria,hyperreninemia and with normal or low blood pressure.Among them,3 cases were accompanied with hypomagnesemia and 2 cases with supine hyperaldosterone.There were 6 SLC12A3 gene mutations and 2 CLCNKB gene mutations,of which 2 gene mutations were new.Conclusions:1.The common causes of hypokalemia in the Endocrinology Department are diabetes-related,insufficient intake,digestive tract loss,hyperthyroidism and aldosteronism.And diabetes-related hypokalemia is the most.The hypokalemia caused by these causes is mainly mild.2.Hereditary hypokalemia is not uncommon and should be taken seriously.Patients with unexplained hypokalemia should be advised to complete genetic testing.3.Adult BS should be considered in patients with hypokalemia,metabolic alkalosis,renal salt loss,high RAAS system activity and normal or low blood pressure.