Type 2 diabetes mellitus caused by Gitelman syndrome-related hypokalemia: A case report

Hypomagnesemia induces impaired glucose metabolism and insulin resistance in patients with Gitelman syndrome

AIMS

To investigate the contributing factors of impaired glucose metabolism in patients with Gitelman syndrome (GS).

METHODS

This study collected clinical data and conducted oral glucose tolerance tests (OGTT) on 44 GS patients, with 60 non-functioning adrenal incidentaloma (NFAI) patients serving as controls.

RESULTS

Compared to NFAI patients, GS patients exhibited a significantly higher prevalence of impaired glucose metabolism (P < 0.001), with markedly higher homeostasis model assessment of insulin resistance (HOMA-IR), lower quantitative insulin sensitivity check index, and lower Matsuda index compared to NFAI patients (all P < 0.001). The homeostasis model assessment for β cells was elevated (P = 0.003) and the insulin secretion sensitivity index-2 was reduced (P = 0.007) in GS patients relative to NFAI patients. Logistic regression identified hypomagnesemia (P = 0.042) and hypokalemia (P = 0.046) as risk factors for dysregulated glucose metabolism in GS patients. Additionally, higher body mass index (BMI) (P = 0.016) and hypomagnesemia (P = 0.045) were significant contributors to IR. Notably, GS patients had a steeper linear regression slope between BMI and HOMA-IR compared to NFAI patients (P = 0.016). A negative linear correlation between plasma magnesium and BMI (R = 0.54, P < 0.001) was found in GS patients.

CONCLUSIONS

Hypomagnesemia may contribute to increased BMI, exacerbating impaired glucose metabolism and IR in GS patients.

Intriguing association between type 1 diabetes mellitus, Gitelman syndrome and Cacci-Ricci disease: Triad of rare diseases: A case report

We report the case of a patient who exhibits a concurrent diagnosis of type 1 diabetes mellitus, Gitelman syndrome and Cacci-Ricci disease. A 27-year-old male patient was diagnosed with Gitelman syndrome at the age of 3 years. Fourteen years later, he developed an autoantibody-negative type 1 diabetes mellitus. Cacci-Ricci's disease was revealed by terminal hematuria and considered in view of the appearance found on the computed tomography (CT) scan. The finger-prick blood glucose level was 6 g/dl with no acetonuria. Creatinine clearance was 60 ml/min. Thyroid function tests were normal. Calcium, phosphorus and parathormone (PTH) levels were normal. Discussion: Gitelman syndrome is a rare disorder. The association between Gitelman syndrome and type 1 diabetes mellitus has been reported in the literature in two patients. Authors have investigated the association between Gitelman syndrome and type 2 diabetes mellitus. Several pathophysiological explanations have been put forward. Cacci-ricci disease is a rare, benign congenital anomaly. No association between type 1 diabetes mellitus, Gitelman syndrome and Cacci-Ricci disease has been reported in the literature. To our knowledge, this is the first case described in the literature.

Effects of co-supplementation of chromium and magnesium on metabolic profiles, inflammation, and oxidative stress in impaired glucose tolerance

PURPOSE

To evaluate the effects of chromium (Cr) and magnesium (Mg) ions on metabolic profiles, inflammation, and oxidative stress with impaired glucose tolerance (IGT) and insulin resistance (IR).

METHODS

120 individuals with IGT and IR were randomly divided into four groups treated with (1) chromium, (2) magnesium, (3) chromium and magnesium or (4) placebo. Metabolic and inflammatory indicators were measured at baseline and after 3 months intervention.

RESULTS

Comparison among groups showed that fasting plasma glucose (FPG), 2 h post glucose (2hPPG), fasting insulin (FINS) and homeostatic model assessment for insulin resistance (HOMA-IR) in Cr + Mg group were significantly decreased compared with the other three groups (p < .05), and high density lipoprotein (HDL-c) levels were higher. 8-iso prostaglandin F2 alpha (8-iso-PGF2a) decreased in Cr, Mg, and Cr + Mg groups compared with placebo (p < .05), and 8-iso-PGF2a decreased in Cr + Mg groups compared with Cr group and Mg groups (p > .05). Intra-group comparison showed that the levels of FPG, 2hPPG and FINS in Cr + Mg group were significantly decreased after intervention (p < .05), and FINS in Mg group was significantly decreased (p < .01). The levels of HDL-c and triacylglycerol (TG) in Cr + Mg group were significantly improved (p < .05). The level of HDL-c in Mg group was significantly improved compared with baseline (p < .05). Compared with baseline, high-sensitivity C-reactive protein (hsCRP) levels in Cr + Mg group and Mg group were significantly decreased (p < .05).

CONCLUSIONS

The co-supplementation of Cr and Mg improves glycemic and lipid levels and reduces the inflammatory response and oxidative stress profiles of individuals with impaired glucose tolerance and insulin resistance.

Case report: Gitelman syndrome with diabetes: Confirmed by both hydrochlorothiazide test and genetic testing

RATIONALE

Gitelman syndrome (GS) is an autosomal recessive tubulopathy caused by mutations of the SLC12A3 gene. It is characterized by hypokalemic metabolic alkalosis, hypomagnesemia and hypocalciuria. Hypokalemia, hypomagnesemia, and increased renin-angiotensin-aldosterone system (RAAS) activity can cause glucose metabolism dysfunction. The diagnosis of GS includes clinical diagnosis, genetic diagnosis and functional diagnosis. The gene diagnosis is the golden criterion while as functional diagnosis is of great value in differential diagnosis. The hydrochlorothiazide (HCT) test is helpful to distinguish GS from batter syndrome, but few cases have been reported to have HCT testing.

PATIENT CONCERNS

A 51-year-old Chinese woman presented to emergency department because of intermittent fatigue for more than 10 years.

DIAGNOSES

Laboratory test results showed hypokalemia, hypomagnesemia, hypocalciuria and metabolic alkalosis. The HCT test showed no response. Using next-generation and Sanger sequencing, we identified 2 heterozygous missense variants (c.533C > T:p.S178L and c.2582G > A:p.R861H) in the SLC12A3 gene. In addition, the patient was diagnosed with type 2 diabetes mellitus 7 years ago. Based on these findings, the patient was diagnosed with GS with type 2 diabetic mellitus (T2DM).

INTERVENTIONS

She was given potassium and magnesium supplements, and dapagliflozin was used to control her blood glucose.

OUTCOMES

After treatments, her fatigue symptoms were reduced, blood potassium and magnesium levels were increased, and blood glucose levels were well controlled.

LESSONS

When GS is considered in patients with unexplained hypokalemia, the HCT test can be used for differential diagnosis, and genetic testing can be continued to confirm the diagnosis when conditions are available. GS patients often have abnormal glucose metabolism, which is mainly caused by hypokalemia, hypomagnesemia, and secondary activation of RAAS. When a patient is diagnosed with GS and type 2 diabetes, sodium-glucose cotransporter 2 inhibitors (SGLT2i) can be used to control the blood glucose level and assist in raising blood magnesium.

Diabetic ketoacidosis in a patient known with Gitelman syndrome

Gitelman syndrome is a rare hereditary nephropathy, which causes chronic metabolic alkalosis with low potassium and magnesium levels. There is no known coherence between Gitelman syndrome and Type-1 diabetes but patients with both diseases that develop diabetic ketoacidosis might present with normal acid status and receive incorrect treatment. In our case report the patient was known with both diseases and quickly diagnosed and treated but the condition is rare and previously only described in two other case reports.

A novel mutation of SLC12A3 gene causing Gitelman syndrome

A 48-year-old patient with a history of diabetes mellitus, presented to a surgical ward with abdominal pain. She was found to have hypokalemia. Her younger sister had passed away due to sudden cardiac death at the age of 25 years. Further evaluation revealed an elevated trans-tubular potassium gradient suggestive of renal potassium loss, normal blood pressure, hypomagnesemia, hypocalciuria, and alkalosis. Moreover, there was evidence of secondary hyperaldosteronism. Genetic studies revealed two heterozygous mutations of the SLC12A3 gene, including a novel mutation which has not been reported before anywhere in the world. She was treated with intravenous potassium supplementation and was later converted to oral potassium and oral magnesium supplementation with spironolactone. Her potassium and magnesium levels normalized and glycaemic control also improved. Hypokalemia and hypomagnesemia found in Gitelman syndrome may be associated with insulin resistance and correction of electrolytes can lead to better glycaemic control.

METFORMIN-AND GLICLAZIDE-BASED DIABETES TREATMENT EXPERIENCE IN A PATIENT WITH GITELMAN SYNDROME

INTRODUCTION

Gitelman Syndrome (GS) is a genetic tubulopathy frequently linked with insulin resistance. The possibility of developing Diabetes Mellitus (DM) in GS increases with the causes of insulin resistance. Hypokalemia is one of the most common electrolyte disorders in GS, and most diabetic drugs can cause hypokalemia. Considering this dilemma, we presented a DM treatment experience in a GS case.

CASE PRESENTATION

A 47-year-old male GS patient with a potassium-rich diet complained of weight loss and dry mouth for 2-3 months. The laboratory tests revealed a higher HbA1c level, as high as 11.8%. The remaining abnormal laboratory test results (hypokalemia, hypomagnesemia, metabolic alkalosis) indicated a patient with GS. The patient was placed on a metformin+gliclazide-based treatment. Oral potassium and magnesium supplementation were started for the patient whose hypokalemia increased in the first control, and the potassium dose was doubled in the third control. In the first-month follow-up visit, it was observed that the blood potassium level was improved, and hyperglycemia was optimized.

CONCLUSION

In brief, any treatment for DM can be selected in GS patients with DM by performing frequent electrolyte monitoring. Like our case, oral potassium supplementation was adequate for the metformin + gliclazide combination-coincidence hypokalemia.

Whole-exome sequencing in diagnosing 2 cases of Gitelman syndrome

Two patients with Gitelman syndrome were admitted to the Department of Endocrinology, Third Xiangya Hospital of Central South University. The genomic DNA from the patients' peripheral blood was extracted and the whole-exome sequencing was performed to detect the possible mutations. The function of the mutation sites was analyzed by bioinformatics software. Through whole-exome sequencing and Sanger sequencing, we have found that 2 patients with Gitelman syndrome carried compound heterozygous mutations of SLC12A3 gene, which were c.486_490delTACGGinsA, p.R943W, p.D486N, and p.R928C. Among them, c.486_490delTACGGinsA insertion deletion mutation causes frame shift and protein truncation. The p.R943W, p.D486N, and p.R928C of SLC12A3 gene were predicted to be pathogenic mutations by SIFT, PolyPhen2, and Mutation Taster. These 4 mutations were all reported, but p.R943W was first reported in Chinese population. Gitelman syndrome is rare in clinic and the rate of missed diagnosis is high. Early genetic analysis in patients with Gitelman syndrome is helpful to determine the etiology and guide the treatment.

Hypokalemia in Diabetes Mellitus Setting

Diabetes mellitus is a public health problem that affects millions of people worldwide regardless of age, sex, and ethnicity. Electrolyte disturbances may occur as a consequence of disease progression or its treatment, in particular potassium disorders. The prevalence of hypokalemia in diabetic individuals over 55 years of age is up to 1.2%. In patients with acute complications of diabetes, such as diabetic ketoacidosis, this prevalence is even higher. Potassium disorders, either hypokalemia or hyperkalemia, have been associated with increased all-cause mortality in diabetic individuals, especially in those with associated comorbidities, such as heart failure and chronic kidney disease. In this article, we discuss the main conditions for the onset of hypokalemia in diabetic individuals, briefly review the pathophysiology of acute complications of diabetes mellitus and their association with hypokalemia, the main signs, symptoms, and laboratory parameters for the diagnosis of hypokalemia, and the management of one of the most common electrolyte disturbances in clinical practice.

Gitelman syndrome with a novel frameshift variant in SLC12A3 gene accompanied by chronic kidney disease and type 2 diabetes mellitus

Gitelman syndrome is an autosomal recessive genetic disease caused by pathogenic variants in SLC12A3 resulting in the loss of function of the Na-Cl co-transporter (NCC) in the distal tubules. Hypokalemia and diuretic effects can cause secondary type 2 diabetes and renal function decline. Here, we present the case of a 49-year-old male patient with chronic persistent treatment-resistant hypokalemia for the past 13 years who had been receiving treatment for type 2 diabetes mellitus for 6 years. He was referred to our department due to the presence of urinary protein, impaired renal function, high renin activity, and hyperaldosteronism. Laboratory test results showed hypokalemia, hypomagnesemia, hypocalciuria, and metabolic alkalosis. Using next-generation and Sanger sequencing, we identified a novel stop-gain variant (NM_000339.3:c.137del [p.His47fs]) and a missense variant (NM_000339.3:c.2927C > T [p.Ser976Phe]) in the SLC12A3 gene. This novel pathogenic variant was located at the intracellular N-terminus of the NCC. Based on these findings, the patient was diagnosed with Gitelman syndrome. The use of next-generation sequencing facilitated the exclusion of diseases with similar clinical symptoms.