The aim of this study was to determine the effects of a 7-day fasting period on acid-base balance in people with type 1 diabetes. Fasting processes produce increased quantities of organic acids, mostly renally buffered and eliminated via enhanced net acid excretion (NAE). We aimed examining whether fasting produces a higher endogenous acid load measured as NAE in people with type 1 diabetes compared to fasting in healthy controls. 17 people with type 1 diabetes, aged 42–56 years, and 9 healthy controls (age range: 23–66 years) were included in the present pilot study of a 7-day fasting period. On day 0, 2, 5 and 8, 24-hour urine collections were carried out and NAE, pH, organic acids, citrate, urea, and creatinine were measured in the samples. Additionally, creatinine clearance, energy intake, and dietary potential renal acid load (PRAL), blood glucose and ketone bodies were assessed. The 24-hour urine pH, excretion rates of organic acids, NAE, and urea, creatinine clearance as well as blood glucose and ketone bodies were not significantly different in people with type 1 diabetes from fasting values in healthy controls. However, energy intake, dietary PRAL and citrate were modestly, but significantly different in people with type 1 diabetes than in healthy controls during fasting. Controlled fasting with appropriate alkaline fluids might even reduce endogenous acid production for all participants in comparison to non-fasting. People with type 1 diabetes may not be at an increased risk of a high endogenous acid production during fasting periods of at least one week, even though they produce fasten-related ketone bodies. • Historically, fasting for several days was considered too risky for individuals with type 1 diabetes. • Fasting uses the physiological ability of human beings to switch to ketogenic fuel. • Berger et al.'s pilot study demonstrated the feasibility of fasting for individuals with type 1 diabetes. • This embedded study assesses the risk of hyperacidity during fasting for type 1 diabetics compared to metabolically healthy participants. • Throughout the fasting period, participants with diabetes exhibited ketone body levels averaging 1.59 mmol/l (range: 0.04 - 5.98 mmol/l). Controls showed higher overall values at 2.79 mmol/l (range: 0.00 - 6.28 mmol/l). • Endogenous acid production of participants with diabetes during fasting was not increased, but even slightly decreased. • Individuals with type 1 diabetes do not face an elevated risk of heightened endogenous acid production during fasting periods of at least one week, despite producing fasting-related ketone bodies.
Baumann et al. (Wed,) studied this question.