medwireNews: Intermittent fasting, following a 5:2 pattern alongside weekly diabetes supervision and reduced medication, doubles the likelihood of experiencing hypoglycemia on fasting days in obese individuals with type 2 diabetes, study data show.
“The overall risk of hypoglycaemia on both fasting and non-fasting days, however, was lower than expected, there were no episodes of severe hypoglycaemia, and most participants did not experience hypoglycaemia,” Brian Corley (University of Otago Wellington, New Zealand) and colleagues report in Diabetic Medicine.
The researchers explain that intermittent 5:2 diets, which involve 2 days of very low calorie intake per week, have become popular in recent years, but can be daunting in people with diabetes due to the increased risk for hypoglycemia caused by changing medication requirements.
To investigate the degree of risk, Corley and team randomly assigned 37 individuals with type 2 diabetes, a BMI of 30–45 kg/m2, and a glycated hemoglobin (HbA1c) level of 6.7–10.0% to adhere to a fasting diet on 2 consecutive (n=18) or non-consecutive (n=19) days per week for 12 weeks. Patients were receiving metformin and/or hypoglycemic medications at baseline.
The participants were given recipe ideas for the fasting days that were developed by a dietician and structured as two small snacks and one light meal, amounting to between 2092 and 2510 kJ per day.
Each participant also received information on the management of hypoglycemia and the importance of glucose monitoring. Hypoglycemic medication was reduced by 50–70% on fasting days and participants reported details of hypoglycemic events to study investigators on a weekly basis.
Overall there were 53 hypoglycemic events, affecting 15 participants, during 84 days of observation. The mean hypoglycemia rate was 1.4 events over 12 weeks.
Corley et al found that the likelihood of having a hypoglycemic event was a significant 2.05-fold higher on fasting days than on non-fasting days, with crude rates of one event per 37 fasting days, compared with one event per 75 non-fasting days.
Hypoglycemia was also more common, but not significantly so, among the participants assigned to consecutive days of fasting (one event per 43 days) than among those who fasted on non-consecutive days (one event per 80 days), at a relative rate of 1.54.
The intermittent fasting came with benefits, however, with the investigators observing a “clinically relevant reduction” in weight (3.1–3.6 kg), HbA1c (0.6–0.7%), and fasting glucose (1.1–1.3 mmol/L), despite the short duration of the study.
Corley and co-authors conclude that intermittent fasting was associated with a “clinically acceptable risk of hypoglycaemia, when combined with weekly supervision, hypoglycaemia education and medication reduction at baseline.”
They add: “Our study protocol could be adopted for the longer-term studies that will be required to assess the tolerability and sustained efficacy of an intermittent fast.”
By Laura Cowen
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