Tohoku J. Exp. Med., 2016 June, 239(2)

Successful Glycemic Control Decreases the Elevated Serum FGF21 Level without Affecting Normal Serum GDF15 Levels in a Patient with Mitochondrial Diabetes

TAKAAKI MURAKAMI,¹ YOKO UEBA,¹ YUYA SHINOTO,² YASUTOSHI KOGA,³ DAITA KANEDA,⁴ TOMONOBU HATOKO,¹ TOMOKO KATO,¹ SHIN YONEMITSU,¹ SEIJI MURO¹ and SHOGO OKI¹

¹Department of Diabetes and Endocrinology, Osaka Red Cross Hospital, Osaka, Osaka, Japan
²Department of Neurology, Osaka Red Cross Hospital, Osaka, Osaka, Japan
³Department of Pediatrics and Child Health, Kurume University School of Medicine, Kurume, Fukuoka, Japan
⁴Department of Neurology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan

Mitochondrial diabetes mellitus is a subtype of diabetes linked to mutations in mitochondrial DNA. In patients with mitochondrial diabetes mellitus, the effect of glycemic control on the serum concentrations of fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15) has not been evaluated. FGF21 and GDF15 have been reported to be useful biomarkers for the diagnosis and severity assessment of mitochondrial diseases like mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Recent studies have shown FGF21 acts in an endocrine fashion to regulate glucose and lipid metabolism in type 2 diabetes mellitus, while the exact biological functions of GDF15 remain unknown. Although mitochondrial diabetes mellitus is commonly found in cases with mitochondrial diseases, the comparison of FGF21 and GDF15 levels between those with and without diabetes has not been performed. Here, we report a 24-year-old woman with mitochondrial diabetes mellitus, who showed a high level of serum FGF21, but not serum GDF15, at diagnosis. In our case, liraglutide, a glucagon-like peptide-1 receptor agonist, added to insulin glargine was effective for her glycemic control and showed no adverse effects, including gastrointestinal symptoms and hypoglycemia, during a 14-week observation. The successful glycemic control caused a decrease in the FGF21 level, without affecting the GDF15 level. Thus, we should consider patients' glycemic control levels in using FGF21 values for the diagnosis of mitochondrial diseases. In addition, sustained GDF15 levels during glycemic treatment in our case suggest the usefulness of GDF15 as a marker for clinical severity of muscle-manifested mitochondrial diseases.

keywords —— biomarker; FGF21; GDF15; GLP-1 receptor agonist; mitochondrial diabetes mellitus

© 2016 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2016, 239, 89-94

Correspondence: Takaaki Murakami, M.D., Department of Diabetes and Endocrinology, Osaka Red Cross Hospital, 5-30 Fudegasaki-cho, Tennoji-ku, Osaka 543-0027, Japan.

e-mail: t.murakami@osaka-med.jrc.or.jp