The Dawn Phenomenon: Variability in Occurrence May Cause Need for Change in Treatment Strategy

Abstract

Schmidt et al ( 1. Schmidt M.I. Hadji-Georgopoulos A. Rendell M. Margolis S. Kowarski A. The dawn phenomenon, an early morning glucose rise: implications for diabetic intraday blood glucose variation. Diabetes Care. 1981; 4: 579-585 Crossref PubMed Scopus (147) Google Scholar ) defined “dawn phenomenon” as the night to morning elevation of blood glucose (BG) before and, to a larger extent, after breakfast in subjects with type 1 diabetes (T1D). A similar observation was made in type 2 diabetes (T2D) by Bolli et al in 1984 ( 2. Bolli G.B. Gerich J.E. The “dawn phenomenon”—a common occurrence in both non-insulin-dependent and insulin-dependent diabetes mellitus. N Engl J Med. 1984; 310: 746-750 Crossref PubMed Scopus (181) Google Scholar ). In normal, non-diabetic subjects ( 3. Kruszynska Y.T. Home P.D. Night-time metabolic changes in normal subjects in the absence of the dawn phenomenon. Diabete Metab. 1988; 14: 437-442 PubMed Google Scholar , 4. Schmidt M.I. Lin Q.X. Gwynne J.T. Jacobs S. Fasting early morning rise in peripheral insulin: evidence of the dawn phenomenon in nondiabetes. Diabetes Care. 1984; 7: 32-35 Crossref PubMed Scopus (59) Google Scholar , 5. Bolli G.B. De Feo P. De Cosmo S. et al. Demonstration of a dawn phenomenon in normal human volunteers. Diabetes. 1984; 33: 1150-1153 Crossref PubMed Google Scholar ), there is not a rise in glucose, due to a documented rise in insulin. Ever since the first description, the dawn phenomenon has been studied extensively. In T1D, the magnitude of BG elevation at dawn first reported was substantial, largely due to the decrease in plasma insulin concentration overnight ( 1. Schmidt M.I. Hadji-Georgopoulos A. Rendell M. Margolis S. Kowarski A. The dawn phenomenon, an early morning glucose rise: implications for diabetic intraday blood glucose variation. Diabetes Care. 1981; 4: 579-585 Crossref PubMed Scopus (147) Google Scholar ), commonly observed with evening administration of Lente or Neutral Protamine Hagedorn insulins ( 6. Owens D.R. Bolli G.B. Beyond the era of NPH insulin–long-acting insulin analogs: chemistry, comparative pharmacology, and clinical application. Diabetes Technol Ther. 2008; 10: 333-349 Crossref PubMed Scopus (72) Google Scholar ). Even early studies with the biostator suggested a significant dawn phenomenon, due in part to an artifact caused by degradation of insulin over time in the biostator ( 7. Brennan J.R. Gebhart S.S. Blackard W.G. Pump-induced insulin aggregation. A problem with the Biostator. Diabetes. 1985; 34: 353-359 Crossref PubMed Scopus (60) Google Scholar ). More recent studies using continuous subcutaneous insulin infusion (CSII) or long-acting insulin analogs have suggested an increase of 25 to 50 mg/dL as the magnitude of the dawn phenomenon ( 8. Bending J.J. Pickup J.C. Collins A.C. Keen H. Rarity of a marked “dawn phenomenon” in diabetic subjects treated by continuous subcutaneous insulin infusion. Diabetes Care. 1985; 8: 28-33 Crossref PubMed Scopus (30) Google Scholar , 9. Perriello G. De Feo P. Torlone E. et al. The dawn phenomenon in type 1 (insulin-dependent) diabetes mellitus: magnitude, frequency, variability, and dependency on glucose counterregulation and insulin sensitivity. Diabetologia. 1991; 34: 21-28 Crossref PubMed Scopus (82) Google Scholar , 10. De Feo P. Perriello G. Ventura M.M. et al. Studies on overnight insulin requirements and metabolic clearance rate of insulin in normal and diabetic man: relevance to the pathogenesis of the dawn phenomenon. Diabetologia. 1986; 29: 475-480 Crossref PubMed Scopus (53) Google Scholar ).