Distribution and influential factors of serum lactic acid levels in healthy Tibetan adults in Lhasa

Abstract

Objective To observe the distribution and influential factors of serum lactate levels in healthy Tibetan adults in Lhasa (average elevation of 3 680 m). Methods From 2015 May to 2016 December, One thousand volunteers from Lhasa and surrounding areas were enrolled into this study conducted by Department of Endocrinology, People's Hospital of Tibet Autonomous Region. The height, weight, waist circumference, systolic blood pressure and diastolic blood pressure were recorded, and body mass index (BMI) was calculated. Fasting blood glucose (FPG), glycated hemoglobin A1c (HbA1c), triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), serum uric acid (UA) and 2 h blood glucose in 75 g oral glucose tolerance test (OGTT) were measured. Fasting serum lactate levels were measured after serum centrifugation. The distribution of blood lactate was analyzed with the data of volunteers with normal blood glucose, blood pressure and blood lipids. Continuous data were compared with the Mann-Whitney U test. The association between other factors and blood lactate was analyzed with spearman correlation and the risk factors associated with blood lactate was analyzed with multivariate linear regression. Results A total of 438 healthy subjects were finally enrolled in the study [158 males and 280 females, average age (45±15 years)]. Lactate levels in fasting venous blood were skewed distribution, with a median (upper and lower quartiles) of 2.15 (1.63, 2.85) mmol/L, and a reference range of 1.00-4.91 mmol/L. Blood lactate level in males was 2.49 (1.92, 3.12), significantly higher than that in females [1.94 (1.52, 2.69) mmol/L] (Z=-4.762, P 0.05). Conclusion The distribution range of serum lactate in normal Tibetan adults in Lhasa range was from 1.00 to 4.91 mmol/L. Blood lactate level was significantly higher in males than in females, and blood lactate levels were inversely correlated with age and FPG. Key words: Lactic acid; Lhasa; Tibetan; Healthy adults