摘要

Background. To examine whether time of the day has an effect on the circulating levels of metabolism parameters. Methods. Venous blood samples were obtained under standardized conditions from 24 healthy young men every third hour through 24 hours. The metabolic markers and melatonin were examined at each time-point and data were analyzed by rhythmometric statistical methods. Results. The normal 24-h rhythms of the participants were confirmed by significant oscillation of melatonin (p < 0.0001). Cosinor analysis revealed significant diurnal 24-h rhythms of five of the seven examined markers: Total cholesterol (p = 0.01, amplitude (amp) = 0.18 mmol/L) peaking in the early afternoon, Glucose (p < 0.0001, amp = 0.35 mmol/L) peaking around midnight, C-peptide (p < 0.001, amp = 360 pmol/L), triglyceride (p < 0.0001, amp = 0.37 mmol/L) peaking in the afternoon and low-density lipoprotein cholesterol (p = 0.003, amp = 0.16 mmol/L) peaking in the morning. C-peptide, triglyceride, and glucose had the highest 24-h oscillations in proportion to the reference ranges of the parameters for healthy young men. Glycated haemoglobin (HbA1c) (p = 0.07, amp = 0.57 mmol/L) and high-density lipoprotein (p = 0.09, amp = 0.06 mmol/L) did not show significant oscillations. Conclusions. When diagnosing and monitoring metabolic disorders compensation for the 24-h variation of the biochemical metabolic markers is needed especially C-peptide, triglyceride and glucose. Furthermore, the stable HbA1c level through 24 h makes it an accurate diagnostic test for diabetes mellitus.

  • 出版日期2015