Serum Glucose Measurement after Five to Six Hours is Comparable to Eight Hours Fasting in Ramadan.

Abstract

ObjectivesThis study aimed to evaluate whether a shorter fasting duration of five to six hours can be used as an alternative to the usually recommended eight hours for fasting glucose measurement.MethodsThis one-month observational, cross-sectional study was conducted during Ramadan (May to June) 2019. It included those attending Faiha Specialized Diabetes, Endocrine and Metabolism Center, Basrah, Iraq; all individuals ate a pre-dawn meal (suhoor) followed by a complete fast for many hours. Two fasting serum glucose (FSG) venous samples were taken; the first was taken five to six hours and the second eight hours after the pre-dawn meal. Participants were divided into two groups: individuals with type 2 diabetes mellitus (T2DM) and those with a normal glucose level. T2DM patients were further subdivided into three groups: those without treatment, those on oral antidiabetic drugs (OAD) and those using insulin and OAD.ResultsA total of 200 individuals participated in this study. There was no significant difference found between the mean FSG levels in the first and second samples for those without T2DM (104.5 ± 21.4 mg/dL versus 104.8 ± 12.6 mg/dL; P = 0.80) as well as those with T2DM (235.0 ± 107.0 mg/dL versus 230.0 ± 105.0 mg/dL; P = 0.20). Untreated T2DM patients had non-significant FSG readings for the two samples (194.0 ± 151.5 mg/dL versus 193.9 ± 128.9 mg/dL; P = 0.90). Patients on insulin and OAD showed a similar pattern of FSG (268.0 ± 111.0 mg/dL versus 269.0 ± 114.0 mg/dL). However, the two FSG samples were found to be significantly different among patients on OAD (220.0 ± 78.0 mg/dL versus 207.0 ± 77.0 mg/dL; P = 0.01).ConclusionThe fasting duration of five to six hours can give a comparable measurement of FSG as that obtained after eight hours.