Temporal patterns of hypoglycaemia and burden of sulfonylurea-related hypoglycaemia in UK hospitals: a retrospective multicentre audit of hospitalised patients with diabetes

Abstract

Objectives: To determine whether temporal patterns of hypoglycaemia exist in inpatients with diabetes 'at risk' of hypoglycaemia (those on insulin and/or sulfonylureas), and if so whether patterns differ between hospitals and between these treatments.

Setting: Retrospective multicentre audit of inpatients with diabetes involving 11 acute UK National Health Service (NHS) trusts.

Participants: Capillary blood glucose readings of 3.9 mmol/L or less (hypoglycaemia) for all adult (≥18 years) inpatients with diabetes 'at risk' of hypoglycaemia were extracted from the Abbott PrecisionWeb Point-of-Care Data Management System over a 4-week period. Overall, 2521 readings of 3.9 mmol/L or less (hypoglycaemia) occurring in 866 participants between 1 June 2013 and 29 June 2013 were analysed.

Results: The majority (65%) occurred between 21:00 and 08:59, a pattern common to all Trusts. This was more frequent in sulfonylurea-treated than insulin-treated participants (75.3% vs 59.3%, p=0.0001). Furthermore, hypoglycaemic readings were more frequent between 5:00 and 7:59 in sulfonylurea-treated than insulin-treated participants (46.7% vs 22.7% of readings for respective treatments, p=0.0001). Sulfonylureas accounted for 31.8% of all hypoglycaemic readings. As a group, sulfonylurea-treated participants were older (median age 78 vs 73 years, p=0.0001) and had lower glycated haemoglobin (median 56 (7.3%) vs 69 mmol/mol (8.5%), p=0.0001). Hypoglycaemic readings per participant were as frequent for sulfonylurea-treated participants as for insulin-treated participants (median=2 for both) as were the proportions in each group with ≥5 hypoglycaemic readings (17.3% vs 17.7%).

Conclusions: In all Trusts, hypoglycaemic readings were more frequent between 21:00 and 08:59 in 'at risk' inpatients with diabetes, with a greater frequency in the early morning period (5:00-7:59) in sulfonylurea-treated inpatients. This may have implications for the continuing use of sulfonylureas in the inpatient setting.

Keywords: DIABETES & ENDOCRINOLOGY; INTERNAL MEDICINE.

Figure 1

Temporal patterns of hypoglycaemic readings over the 24 h period in the individual 11 National Health Service (NHS) Trusts. The x axis represents the time period, for example, 0 represents the time period between 00:00 and 00:59, 1 represents the time period between 01:00 and 01:59, etc. The y axis represents the number of hypoglycaemic readings occurring in that time period. The figure demonstrates very similar temporal patterns for all Trusts.

Figure 2

Temporal patterns of hypoglycaemic readings over the 24 h period in all participants on insulin, sulfonylureas and both. The x axis represents the time period, for example, 0 represents the time period between 00:00 and 00:59, 1 represents the time period between 01:00 and 01:59, etc. The y axis represents the number of hypoglycaemic readings occurring in that time period. The figure demonstrates that the highest frequency occurs between 05:00 and 07:59 for both insulin and sulfonylurea therapies.