Magnitude of the Dawn Phenomenon and Its Impact on the Overall Glucose Exposure in Type 2 Diabetes

Abstract

OBJECTIVETo assess the magnitude of the dawn phenomenon and its impact on the total glucose exposure in type 2 diabetes.RESEARCH DESIGN AND METHODSA total of 248 noninsulin-treated persons with type 2 diabetes who underwent continuous glucose monitoring were divided into three groups selected by treatments: diet alone (n = 53); insulin sensitizers alone (n = 82); and insulin secretagogues alone or in combination with insulin sensitizers (n = 113). The dawn phenomenon (∂ glucose, mg/dL) was quantified by its absolute increment from nocturnal nadir to prebreakfast value. The participants were secondarily divided into two paired subsets after they had been separated by the presence/absence of a dawn phenomenon based on a threshold of 20 mg/dL and matched for glucose nadir. The impact of the dawn phenomenon was assessed on HbA1c and 24-h mean glucose.RESULTSThe median of ∂ glucose (interquartile range) was 16.0 (0–31.5 mg/dL) in the 248 subjects, and no differences were observed across groups selected by HbA1c or treatments. In the overall population, the mean impacts on HbA1c and 24-h mean glucose were 4.3 ± 1.3 mmol/mol (0.39 ± 0.12%) and 12.4 ± 2.4 mg/dL, respectively. The mean impact on 24-h mean glucose was not statistically different between those on diet alone (16.7 ± 5.9 mg/dL) compared with the two subsets treated with oral hypoglycemic agents (11.2 ± 5.3 and 8.5 ± 7.5 mg/dL).CONCLUSIONSThe impact of the dawn phenomenon on overall glycemic control in type 2 diabetes, as depicted by the HbA1c level, was ∼0.4% and not eliminated by any of the currently available armamentarium of oral antidiabetes agents.

Response to Comment on Monnier et al. Magnitude of the Dawn Phenomenon and Its Impact on the Overall Glucose Exposure in Type 2 Diabetes: Is This of Concern? Diabetes Care 2013;36:4057–4062

“…The data that we have reported in our article (3) indicate that none of the currently marketed oral antidiabetes medications are capable of adequately controlling the dawn phenomenon even when given as combined therapies. Porcellati et al (4) suggested in their commentary to our article that regimens with long-acting insulin injected once daily in the evening seem the most appropriate therapies for reducing or abolishing the dawn phenomenon.…”

“…As a consequence, these drugs represent a new class of antidiabetes agents; for that reason, we agree that the true terminology is incretin enhancers. Second, these new drugs are also well-recognized insulinotropic glucose-dependent agents, which is why they have been simply classified as insulin secretagogues in our study (3).…”

New insights on glucose homoeostasis during Ramadan

“…This is especially the case in those who exhibit the "dawn phenomenon", a spontaneous early-morning rise in blood glucose [18][19][20]. In diabetics being treated with insulin, any pharmacological treatment should be carefully selected and titrated according to both the patient's eating patterns and the physician's own clinical practices.…”

Effects of Growth Hormone on Diurnal Insulin Sensitivity in Normal and Type 2 Diabetic Patients and Animal Models

“…Differences in the frequency of dawn phenomenon were more evident in T2DM subjects older than age 70 years than in subjects younger than age 70 years, indicating that dawn phenomenon is present in adults aged 70 and older [6]. Monnier et al [7] reported an additional observation on the dawn phenomenon in a large group of patients with T2DM and quantified its role in overall plasma glucose control. This type of morning rise in plasma glucose has also been found in diabetic patients who were treated with diet alone or diet plus sulfonylureas, leading researchers to suggest that factors such as treatment and duration of diabetes may contribute to the pathogenesis of dawn phenomenon [8].…”