Excessive purine degradation during semi-ischemic forearm test in patients with diabetes mellitus.
OBJECTIVE
The aim of this study was to investigate whether or not the purine degradation in the skeletal muscle during forearm exercise is augmented in patients with diabetes mellitus (DM).


METHODS
We used the semi-ischemic forearm test to examine the release of lactate (deltaLAC), ammonia (deltaAmm) and hypoxanthine (deltaHX) before exercise, 0, 4, 10, and 60 minutes after exercise in eleven diabetic patients and seven normal controls.


RESULTS
The sum of the increased HX (DM vs Controls: 26.1 +/- 21.2 vs 7.8 +/- 5.9 micromol/L, p < 0.05) was greater in diabetic patients. When patients were divided into the excessive response group (n = 7) and normal response group (n = 4), the maximum increments in deltaHX and deltaAmm in the excessive response group (16.8 +/- 3.2 micromol/l and 122 +/- 60 micromol/l) were greater (p < 0.05) than those in the control group (3.6 +/- 3.0 micromol/l and 32 +/- 34 micromol/l and the normal response group (2.9 +/- 2.9 micromol/l and 27.4 +/- 12.7 micromol/l). DeltaLAC both in the excessive response group (5.4 +/- 1.5 mmol/l) and the normal response group (3.6 +/- 1.0 mmol/l) were higher (p < 0.05) than that of the control group (1.7 +/- 0.5 mmol/l). The prevalence of diabetic retinopathy was higher in the excessive response group than in the normal response group (75% vs. 25%).


CONCLUSIONS
These data suggest that patients with DM, especially with microangiopathy have augmented purine degradation during the semi-ischemic forearm test. Factors responsible for the augmented purine degradation in these patients remain to be determined.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003920:Diabetes Mellitus / Q000378:metabolism* / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000378:metabolism* / Q000503:physiopathology; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005542:Forearm / Q000098:blood supply; D006801:Humans; D007511:Ischemia / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism*; D011687:Purines / Q000378:metabolism*
D011687:Purines; C030985:purine