Diabetes Care, Vol 19, Issue 12 1423-1425, Copyright © 1996 by American Diabetes Association
Mitochondrial aldehyde dehydrogenase in diabetes associated with mitochondrial tRNA(Leu(UUR)) mutation at position 3243
Y Suzuki, T Muramatsu, M Taniyama, Y Atsumi, M Suematsu, R Kawaguchi, S Higuchi, T Asahina, C Murata, M Handa and K Matsuoka
Saiseikai Central Hospital, Tokyo, Japan. drsuzuki@ba2.so-net.or.jp
OBJECTIVE: To ascertain why alcohol is prone to manifest unpleasant effects
in diabetes associated with mitochondrial tRNA(Leu(UUR) mutation at
position 3243 (DM-Mt3243), we investigated the genotype of aldehyde
dehydrogenase (ALDH) 2 and alcohol dehydrogenase 2 (ADH2) in DM-Mt3243.
RESEARCH DESIGN AND METHODS: Nineteen unrelated patients with DM-Mt3243
were included in the study (12 men and 7 women). They were recruited from
approximately 700 diabetic patients at three different institutes, without
prior information of alcohol habit. ALDH2, ADH2, and 3243 mutation were
genotyped by polymerase chain reaction (PCR)-restriction fragment length
polymorphism (RFLP) methods. There were 461 unrelated Japanese individuals
and 170 non-3243 mutant NIDDM patients enrolled as control subjects.
RESULTS: In the DM-Mt3243 group, 15 (79%) patients had inactive ALDH2 and
18 (95%) had atypical ADH2. The frequency of the inactive ALDH2 genotype
was higher than that in the normal control subjects (P < 0.002) and that
in the NIDDM control subjects (P < 0.003). However, the frequencies of
ADH2 genotype in the DM-Mt3243 group, the normal control subjects, and the
NIDDM control subjects were not different. CONCLUSIONS: Inactive ALDH2
genotype was frequently observed in DM-Mt3243. It suggests that DM-Mt3243
is associated with ALDH2 inactivity. We speculate the trait of acetaldehyde
accumulation on ALDH2 inactivity may favor mitochondrial DNA abnormalities,
thereby worsening ATP production and impairing insulin secretion. In
addition, the interaction of ALDH1 and ALDH2 may alter the retinoid
metabolism in the pancreas, thereby influencing insulin secretion and
precipitating diabetes. Thus, this association of ALDH2 genotype with
DM-Mt3243 provides insight into the etiology of diabetes in the
mitochondrial diseases.