Blood lactate, hepatic histology and microsomal enzyme activity in non-insulin-dependent diabetics

The relationship between blood lactate levels, liver histology and microsomal enzyme activity (cytochrome P-450 content) was assessed in 32 non-insulin-dependent diabetics (NIDD) undergoing diagnostic liver biopsy. Fasting blood lactate was related to liver histology and the mean was in the low normal range in the diabetics with an intact liver, whereas higher values were noted in the diabetics with a fatty liver, inflammatory changes and an increase in fibrous trabeculae. Similarly, in the diabetics with an abnormal liver, there was a tendency for pyruvate to be elevated, and body weights and serum insulin concentrations were higher than in the NIDD with an intact liver. P-450 was inversely related to liver histology and its content was reduced in association with increases in fat and fibrous tissues. P-450 was significantly correlated with lactate (rs -0.79), pyruvate (rs -0.65) and serum insulin (rs -0.53). The results revealed close associations between blood lactate, hepatic structure and microsomal enzyme activity, and emphasize that liver function is an important consideration when lactate metabolism is evaluated in NIDD.