Serum 1,5-anhydroglucitol is low in gastrectomized men

Abstract

Biochemical markers of glycemic control such as HbA1c, glycated albumin (GA), and serum 1,5-anhydroglucitol (1,5-AG) are currently used in the clinical setting. It has been indicated that HbA1c primarily reflects mean plasma glucose (MPG), whereas GA and 1,5-AG represent postprandial glycemic excursions in addition to MPG [1, 2]. It is well known that in gastrectomized subjects, glucose tolerance test often shows marked hyperglycemia 30–60 min after loading, a phenomenon called oxyhyperglycemia [3]. We have demonstrated that GA in gastrectomized subjects is higher than non-gastrectomized subjects [4]. Therefore, it is expected that serum 1,5-AG would be lower in gastrectomized subjects, although no studies have investigated this expectation. In the present study, we determined whether or not serum 1,5-AG levels are low in gastrectomized subjects. Of individuals who underwent a health examination at Kinki Central Hospital, 26 non-diabetic men with a history of gastrectomy (age: 61.0 ± 7.3 years, BMI: 21.6 ± 2.4 kg/m, HbA1c: 5.7 ± 0.3%) and 63 non-diabetic men without a history of gastrectomy (control, age: 59.4 ± 0.9 years, BMI: 23.8 ± 2.5 kg/m, HbA1c: 5.7 ± 0.3%) were included in this study. Subjects in both groups who were being treated for diabetes and those who were diagnosed as diabetes mellitus by oral glucose tolerance test (OGTT) according to the definition of American Diabetes Association (ADA) at 2010 [5] were excluded. The controls were matched to the gastrectomized group for age and HbA1c levels. HbA1c was measured by HPLC. The value for HbA1c (%) was estimated as a National Glycohemoglobin Standardization Program (NGSP) equivalent value (%) calculated using the formula: HbA1c (%) = HbA1c (Japan Diabetes Society: JDS) (%) ? 0.4%; considering the relational expression of HbA1c (JDS) (%) measured by the previous Japanese standard substance and measurement methods and HbA1c (NGSP) [6]. GA was determined by an enzymatic method using albumin-specific proteinase, ketoamine oxidase, and albumin assay reagent (Lucica GA-L; Asahi Kasei Pharma Co., Tokyo, Japan). Serum 1,5-AG was measured using an enzymatic method with a Lana 1,5AG Auto Liquid Kit (Nippon Kayaku, Tokyo, Japan), as described previously [7]. Data are shown as means ± SD or medians (interquartile range). For statistical analyses, the Student’s t test or Mann–Whitney U test was used to compare two groups. To analyze the effects of explanatory variables on serum 1,5-AG (log transformed), stepwise multivariate regression analysis (step up method) was performed. In the stepwise multivariate regression analysis, the F-value for the inclusion of the variables was set at 4.0. P values of\0.05 were considered statistically significant. Although fasting plasma glucose did not significantly differ between both groups (gastrectomized men: 95.2 ± 8.1 mg/dl vs. controls: 95.2 ± 8.1 mg/dl; P = 0.223), OGTT 2-h glucose in the gastrectomized men was significantly lower than in the control men (83.8 ± 38.6 mg/dl vs. 121 ± 19 mg/dl; P \ 0.001). GA (gastrectomized men: 15.4 ± 1.0% vs. controls: 14.5 ± 1.0%; P \ 0.001) was significantly higher in the gastrectomized men than in the controls men. J. Murai M. Koga (&) H. Saito M. Mukai Department of Internal Medicine, Kinki Central Hospital, Hyogo, Kuruma-zuka 3-1, Itami, Hyogo 664-8533, Japan e-mail: koga_m@kich.itami.hyogo.jp