Titrating beyond glycemic goal: "post-glycemic target phenomenon"

Omitting late-night eating may cause hypoglycemia in "well controlled" basal insulin-treated type 2 diabetes

OBJECTIVE

To assess hypoglycemia caused by eating the last meal of the day earlier or its omission in "well controlled" type 2 diabetes mellitus patients treated with once-nightly basal insulin.

METHODS

Previously basal insulin-titrated subjects (n = 20) (fasting plasma glucose, FPG, <110 mg/dL and no self-reported hypoglycemia) underwent continuous glucose monitoring (CGM) during 3 consecutive eating conditions of 3 days each; (1) usual eating, (2) the last meal restricted to 18:00, and (3) 1 sequential meal omitted/day thereby creating a fasting day after transposing the 4-hour period after a meal with that when the meal was omitted. One 24-hour (00:00 to 00:00) period within each eating condition was selected for comparison.

RESULTS

The mean duration in all hypoglycemic ranges doubled (P = .0584 or greater) when the last meal was omitted or eaten at 18:09 ± 0:39 instead of 19:43 ± 1:01, the usual time for the subjects' undisturbed eating. The mean duration of hypoglycemia was greatest between 00:00 to 06:00 compared to the 3 other 6-hour periods of the day.

CONCLUSIONS

Increased hypoglycemia occurs when the subject's last meal is eaten earlier or omitted and may not be recognized because it occurs predominately during sleep. When titrating basal insulin from the morning FPG, considerations should be given to the effect of the last meal of the day and possible hypoglycemia between 00:00 and 06:00 to avoid excessive basal insulin treatment.

Misled by the Morning "Fasting" Plasma Glucose

Because of its ease and simplicity of its measurement, the morning fasting plasma glucose (FPG), has been as used a surrogate marker for the entire basal day when titrating once-nightly basal insulin. Common in obese insulin-treated patients with type 2 diabetes, late and large evening meals elevate the FPG. This has led to dosing of basal insulin well beyond the basal requirements and contributes to hypoglycemia and weight gain seen with this therapy. It is recommended that during basal insulin titration, the evening meal be limited and hypoglycemia be monitored early in the morning, that bewitching time when the "peakless" basal insulin's action is peaking and the predawn phenomenon insulin sensitivity is higher.