# Metabolic Myopathies and HyperCKemia in Adulthood: A Clinical Approach to Diagnosis and Management

## TL;DR

This paper discusses how elevated creatine kinase levels in adults can indicate metabolic muscle diseases and emphasizes the importance of early diagnosis and treatment.

## Contribution

The paper provides a clinical overview of metabolic causes of hyperCKemia in adults, emphasizing diagnostic approaches and management strategies.

## Key findings

- Metabolic myopathies often present with nonspecific or exercise-related symptoms and variable creatine kinase elevations.
- Conditions like McArdle disease and mitochondrial cytopathies have distinct metabolic vulnerabilities leading to hyperCKemia.
- Early diagnosis through biochemical and genetic testing can lead to targeted therapies and improved outcomes.

## Abstract

Background: HyperCKemia, defined as elevated serum creatine kinase, commonly reflects muscle injury but may also indicate underlying metabolic disease. Metabolic aetiologies, including glycogen storage disorders, fatty acid oxidation defects, mitochondrial cytopathies, and purine metabolism disorders, are clinically important owing to diagnostic complexity, therapeutic implications, and potential reversibility. Objective: To summarise current evidence on metabolic causes of hyperCKemia in adults, with emphasis on disorders of carbohydrate, lipid, and purine metabolism and mitochondrial disease. Methods: Semi-systematic narrative review of pathophysiology, clinical features, diagnostic approaches, and management of metabolic disorders associated with hyperCKemia. Results: Metabolic myopathies often present with nonspecific or exercise-related symptoms, with creatine kinase levels ranging from mild-to-severe elevations. Conditions such as McArdle disease, carnitine palmitoyltransferase II deficiency, and mitochondrial cytopathies demonstrate characteristic metabolic vulnerabilities leading to episodic or persistent hyperCKemia. Medications, including statins and antiretrovirals, may precipitate symptoms in predisposed individuals. Diagnosis requires a structured, multidisciplinary approach incorporating biochemical testing, genetic analysis, functional studies, and muscle biopsy. Many causes are amenable to targeted therapy, including dietary modification, endocrine correction, and medication withdrawal. Conclusion: Metabolic causes of hyperCKemia are under-recognised but clinically significant. Early identification allows targeted treatment and prevention of complications.