Thyrotoxic hypokalemic periodic paralysis (THPP) is a rare but potentially fatal complication of thyrotoxicosis, characterized by transient episodes of muscle weakness in the setting of hypokalemia and underlying hyperthyroidism. Although thyrotoxicosis is more common in females, THPP predominantly affects males, especially in Asian populations, in which its prevalence is notably higher. Early recognition is essential to prevent serious complications such as cardiac arrhythmias and respiratory failure; however, THPP is frequently misdiagnosed, particularly in Western countries, due to clinical overlap with familial hypokalemic periodic paralysis. The pathophysiology of THPP involves thyroid hormone–induced upregulation of Na+/K+-ATPasease and heightened β-adrenergic sensitivity, which promote intracellular potassium shifts. Postprandial insulin surges following high carbohydrate intake further exacerbate this effect. Genetic susceptibility, including human leukocyte antigen haplotypes and mutations in ion channel genes (e.g., KCNE3, CACNA1S, SCN4A, and KCNJ18), plays a critical role. The resulting hypokalemia leads to hyperpolarization of muscle membranes, impairing excitability and causing paralysis. Structural muscle changes, such as sarcoplasmic reticulum proliferation and sodium channel dysfunction, may also contribute to THPP. Electrolyte abnormalities, including hypophosphatemia, hypomagnesemia, and hypocalcemia, are common due to transcellular shifts. This review underscores the importance of understanding the hormonal, genetic, and cellular mechanisms underlying THPP to enhance diagnostic accuracy and guide effective treatment strategies.

Introduction: Laboratory tests account for 66% of clinical decision making and reducing inappropriate test utilisation is a step towards optimising patients’ care and hospital cost savings. This study aims to identify the rate and cost of redundant test requests in our centre. Methods: A cross-sectional study comprising laboratory results of 14 analytes in renal function test (RFT) and liver function test (LFT) were made. Data involved blood results from adult patients admitted to Hospital Universiti Sains Malaysia from January to December 2018. The redundant test is defined as test results consecutively normal twice and requested within 26 hours for analytes in RFT and 50 hours for analytes in LFT. Cost contributions were estimated by multiplying cost-per-test with total redundant requests. The test redundancy in different wards and disease groups were also evaluated. Results: Equal distribution of RFT and LFT requests were observed in both genders (50% respectively), with the most requests seen in the 60 – 79 years age group. More than 20% redundancy rate was observed for seven analytes (ALT, total bilirubin, sodium, urea, potassium, AST, Chloride), and overall redundancy was 19.7%, equals to Malaysian Ringgit (MYR) 669,105.00. Oncology wards and genitourinary diseases contribute to the highest redundancy rate. Conclusion: This study estimated MYR 600 thousands of saving if test redundancy were to be eliminated. The finding is hoped to serve as a platform for future intervention and policymaking. Future planning to optimise the current laboratory request system and collaboration among physicians and laboratory professionals can minimise test inappropriateness.

The gonadotropin-releasing hormone (GnRH) stimulation test is a valuable tool in diagnosing and differentiating causes of early pubertal occurrences. Utility of the test can be limited in some instances, however, including the early phases of pubertal hypothalamic-pituitary-gonadal axis activation, in girls showing commonly overlapping pictures, and in obese children due to excess circulating estrogen that suppresses luteinizing hormone (LH). A lack of consistent baseline and stimulated gonadotropin cutoffs observed in different studies also contributes to limitations in testing. Nevertheless, early detection of true pathological causes for pubertal disorders is needed to allow prompt treatment and better prognosis. While basal LH can be beneficial as a good screening tool for detecting pubertal disorder, it does not preclude the need for GnRH testing. The aim of this review was to highlight the role of GnRH stimulation tests and varying testing cutoffs in diagnosis of precocious puberty and its classification.