Incidence of Nocturnal Hypoglycaemia in Insulin‐dependent Diabetic Patients on Intensive Therapy

Abstract

The frequency of nocturnal hypoglycaemia, i.e. blood glucose concentration (BG) <3.0 mmol/l, was evaluated in consecutively selected insulin‐dependent patients on multiple insulin injections (MII), n =23, or continuous subcutaneous insulin infusions (CSII), n =25. Blood was sampled hourly from 23.00 to 07.00. Seven patients (30%) on MII had at least one BG <3.0 mmol/l during the night. Eleven patients (44%) on CSII had hypoglycaemia (NS). The total number of BGs <3.0 mmol/l was higher on CSII, 42 of 225, versus 16 of 207 on MII (p<0.025). The duration of hypoglycaemia was 2 hours (range 1–6) on MII and 4 hours (range 1–7) on CSII with a maximal prevalence at 4 hours and between 5 and 7 hours, respectively (p=<0.05). The frequency of nocturnal hypoglycaemia is high in patients on intensified insulin regimens. Nocturnal hypoglycaemia occurs later in the night and is of longer duration on CSII than on MIL HbA1c, BG before bedtime and in the morning might be useful in the evaluation of nocturnal hypoglycaemia.

Nocturnal hypoglycaemia in Type 1 diabetic patients, assessed with continuous glucose monitoring: frequency, duration and associations

“…Our estimate of the occurrence rate of nocturnal hypoglycaemia in Type 1 diabetic patients, as assessed with the microdialysis sensor, corresponds well with the results reported in previous ward studies [7,8]. However, the estimated duration of nocturnal hypoglycaemia in both our treatment groups was considerably shorter than previously reported ( Table 2).…”

“…In CSII-treated patients, we noted both less frequent occurrence and shorter duration of nocturnal hypoglycaemia ≤ 3.0 mmol/l than reported by Bendtson et al [44 vs. 29% and 240 (60 -420) min. vs. 33 (9 -225) min., see Table 2] [7]. In addition to the explanations noted above, another possible explanation for this difference may be that HbA 1c was lower in the group of Bendtson et al compared with our cohort (7.0 vs. 7.8%), particularly as HbA 1c was significantly associated with the duration of nocturnal hypoglycaemia in our study (P = 0.049).…”

“…For comparison with previous studies, 29% of the CSII (vs. 44% reported by Bendtson et al . [7]) and 21% (vs. 30 and 29% according to Bendtson et al . [7] and Vervoort et al .…”

“…[44 vs. 29% and 240 (60–420) min. vs. 33 (9–225) min., see Table 2][7]. In addition to the explanations noted above, another possible explanation for this difference may be that HbA 1c was lower in the group of Bendtson et al .…”

“…Until recently, the incidence of nocturnal hypoglycaemia, including asymptomatic hypoglycaemia, in Type 1 diabetic patients on intensive insulin therapy, could only be assessed in research ward studies. One study found hypoglycaemia ≤ 3.0 mmol/l during the night in 30% of patients on multiple‐injection therapy (MIT), with a median duration of 2 h per night, and in 44% of patients on continuous subcutaneous insulin infusion (CSII) with a median duration of 4 h per night [7]. Another study found that 29% of patients on MIT experienced hypoglycaemia ≤ 3.0 mmol/l during the night with a mean duration of 1 h per night [8].…”