Kidney Week

Abstract: TH-PO351

Prolonged Hypokalemia Long after Causative Factor Elimination in Pseudo-Bartter/Gitelman Syndrome

Session Information

• Sodium, Potassium, and Volume Disorders: Clinical
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Fluid, Electrolytes, and Acid-Base Disorders

• 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical

Authors

• Kondo, Atsushi, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Atsushi Kondo, MD, PhD

• Horinouchi, Tomoko, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Tomoko Horinouchi, MD, PhD

• Inoki, Yuta, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Yuta Inoki, MD

• Tanaka, Yu, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Yu Tanaka, MD

• Kitakado, Hideaki, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Hideaki Kitakado, MD

• Ueda, Chika, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Chika Ueda, MD

• Sakakibara, Nana, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Nana Sakakibara, MD, PhD

• Nagano, China, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

China Nagano, MD, PhD

• Fujimura, Junya, Kakogawa Chuo Shimin Byoin, Kakogawa, Hyogo, Japan

Junya Fujimura, MD

• Yamamura, Tomohiko, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Tomohiko Yamamura, MD, PhD

• Ishimori, Shingo, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Shingo Ishimori, MD, PhD

• Nozu, Kandai, Kobe Daigaku Daigakuin Igakukei Kenkyuka Igakubu, Kobe, Hyogo, Japan

Kandai Nozu, MD, PhD

Background

Pseudo-Bartter/Gitelman syndrome (PBS/PGS) is a medication- and lifestyle-related disorder characterized by hypokalemia and a tendency to renal dysfunction. Treatment involves the elimination of the causative factor and potassium supplementation. However, PBS/PGS symptoms may persist long after the removal of causative factors, and its pathogenesis remains unclear.

Methods

We included 157 cases in which no pathogenic variant was identified despite comprehensive genetic testing, including targeted next-generation sequencing, for suspected inherited salt-losing tubulopathy. Among these, we examined 49 cases with a clear medical history confirming the cause of PBS/PGS. They were categorized into two groups: the current group (n=39), where causative factors persisted, and the past group (n=10), where more than one year had elapsed since the elimination of the causative factors at the time of examination. A retrospective comparative analysis was conducted between these groups.

Results

All patients were female, except for two in the current group. The median age at the time of genetic testing was 44.0 years (range 16–60 years) in the current group and 37.5 years (range 29–58 years) in the past group. The median time since the elimination of causes in the past group was 7.5 years. Blood tests revealed evident hypokalemia in the current and past groups, with a median of 2.4 vs. 2.6 mEq/L (p=0.51), respectively. Renal dysfunction was observed in both groups, with the median estimated glomerular filtration rate 57.6 vs. 60.7 mL/min/1.73 m² (p=0.84). Notably, overactivation of the renin-angiotensin system was observed in both groups, as evidenced by a median plasma renin activity of 21.2 vs. 13.2 ng/mL/h (p=0.24) and a median plasma aldosterone concentration of 253 vs. 165 pg/mL (p=0.031).

Conclusion

This study is the first to reveal the possibility of persistent PBS/PGS findings even after removing causative factors. Regarding pathogenesis, we suspect that prolonged hypokalemia may result in a low set point for serum potassium levels being fixed in the renal tubules. While swift removal of the cause of PBS/PGS is crucial, long-term post-removal monitoring is essential to improve renal prognosis.

Funding

• Government Support – Non-U.S.