efficacy and safety of a ketogenic diet in type 1 diabetes

Conditions: Diabetes Mellitus, Type 1

Summary: despite strong evidence that tight control of blood sugar reduces the risk of diabetes complications, most people with type 1 diabetes do not achieve recommended blood sugar targets. this randomized controlled trial will test whether a very-low- carbohydrate ketogenic diet can effectively and safely improve blood sugar control in adults with type 1 diabetes.

a very-low-carbohydrate ketogenic diet (≤50 g carbohydrate/day) could reduce glycemic variability, total daily insulin requirement, and hba1c in people with type 1 diabetes (t1d). indeed, several case series and observational studies of using a ketogenic diet (kd) in people with t1d have observed such benefits. however, no randomized controlled trials (rcts) have evaluated the efficacy of kd for \>7 days in people with t1d. in addition, there are serious concerns regarding the safety and tolerability of a kd in patients with t1d, including the potential for an increased risk of hypoglycemia, diabetic ketoacidosis, dyslipidemia, insulin resistance, decreased bone mineral density, and impaired quality of life. this study is a 12-week rct to evaluate the clinical efficacy, metabolic function, safety, socio-behavioral impact, acceptability and potential for dissemination of an isocaloric kd compared with an american diabetes association-recommended control diet in adults with t1d.

Eligibility criteria:
inclusion criteria: * age ≥18 and ≤65 years * t1d diagnosed \>1 year prior to screening * hba1c 7.0%-9.0% * stable insulin delivery method for the past 30 days * ability to read all device instructions and insulin pump settings * egfr ≥60 ml/min/1.73 m2 * use of an insulin pump or insulin delivery by multiple daily injections * use of personal cgm for at least 12 weeks and willing to change to dexcom cgm for the duration of the study, if using a different sensor, to reduce variability in glucose values associated with different cgm products * use of cellular phone with data capability for wireless connectivity to the cgm system. exclusion criteria: * body mass index \ 34.9 kg/m2 * severe gastroparesis or history of bariatric surgery * diabetes-related hospitalization (including for diabetic ketoacidosis or severe hypoglycemia) within 12 months of screening * poorly controlled hypertension (sbp ≥160 mmhg or dbp ≥100 mmhg) * taking diabetes medications, other than insulin (particularly sglt2 inhibitors, which are associated with an increased risk of euglycemic dka) * structured exercise \>210 minutes per week * pregnant, lactating, not using effective birth control if premenopausal, or planning to become pregnant within the 6-month study period * unstable weight (\>4% change in the last 2 months) * significant organ system dysfunction (e.g., severe pulmonary, renal, hepatic, or cardiovascular disease) * anemia (hgb \<10 g/dl) * major psychiatric illness * active tobacco use (\>8 cigarettes/day) or illegal drug use * regular alcohol consumption (\>10 standard drinks per week) * use of medications known to affect the study outcome measures or increase the risk of study procedures that cannot be temporarily discontinued for this study * familial hypercholesterolemia * active eating disorder * dietary restrictions incompatible with a very-low-carbohydrate kd, vegan diet, vegetarian diet, severe lactose intolerance, severe aversion/sensitivity to eggs, fish, nuts, wheat, or soy, and any anaphylactic food allergy * already consuming a low-carbohydrate (\<130 g/day) diet * persons who are not able to grant voluntary informed consent * persons who are unable or unwilling to follow the study protocol or who, for any reason, the research team considers an inappropriate candidate for the study.

Keywords: type 1 diabetes ketogenic diet insulin sensitivity continuous glucose monitoring hypoglycemia