Latest glucose-lowering drug use and glycaemic outcome trends in HK

A retrospective cross-sectional analysis of trends in glucose-lowering drug (GLD) use and glycaemic outcomes among Hong Kong’s 0.9 million adults with diabetes between 2002 and 2019 finds a levelling off in improvements since 2014.

“We previously reported improvements in glycaemic control in 2007–2014 in Hong Kong coinciding with primary care reforms, decreased use of sulphonylureas (SUs) and increased use of dipeptidyl-peptidase 4 [DPP-4] inhibitors and metformin,” wrote the researchers from the Chinese University of Hong Kong. “The aim of this study was to estimate more recent trends in drug use and glycaemic outcomes following introduction of newer classes of GLDs.”

Using population-based data from the Hong Kong Diabetes Surveillance Database (HKDSD), the researchers explored age-specific trends in achievement of glycaemic targets and incidence rates of severe hypoglycaemia (SH) in 963,612 adults with diabetes in 2002–2019. [Lancet Reg Health West Pac 2022;doi:10.1016/j.lanwpc.2022.100509]

The number of patients with diabetes in the HKDSD increased by 3.9 times from 188,974 in 2002 to 753,374 in 2019. The proportion of patients not treated with any medications steadily increased since 2002 at an annual rate of 4.5 percent to reach 24.9 percent in 2019. At the same time, the proportion of patients receiving ≥4 GLDs also increased, reaching 9.5 percent in 2019.

Between 2002 and 2019, metformin use increased from 41.1 percent to 58.7 percent, while insulin use remained broadly static (11.2–13.6 percent). Use of SUs declined at a yearly rate of 3 percent since 2004 and was 31.1 percent in 2019. In 2009–2013, the use of thiazolidinediones (TZDs) declined but began to increase again in 2013, with 6.4 percent of patients on TZDs by 2019.

DPP-4 inhibitors remained the most widely prescribed newer GLDs (14.3 percent) vs sodium glucose co-transporter-2 (SGLT2) inhibitors (4.2 percent) and glucagon-like-peptide 1 receptor agonists (GLP-1 RAs; 0.6 percent) in 2019.

“Use of DPP-4 inhibitors increased rapidly in 2007–2011 [annual percentage change (APC), 188.6 percent], which slowed thereafter,” reported the researchers. “There were sharp increases in use of GLP-1 RAs since 2008 [average APC, 28.7 percent] and SGLT2 inhibitors since 2015 [average APC, 63.7 percent] when these newer therapies were introduced into the Hospital Authority’s Drug Formulary.”

The researchers observed high use of new GLDs including SGLT2 inhibitors and GLP-1 RAs in young patients with the worst glycaemic control and high BMI, while their use was low in patients with atherosclerotic cardiovascular disease and chronic kidney disease. “According to randomized clinical trials’ [RCT] data, newer GLDs have similar efficacy and safety in older and younger adults. However, lower use of SGLT2 inhibitors in real-world practice might reflect physicians’ tendency to de-intensify treatment in old adults and concerns over side effects [that may occur] without the close supervision typical of RCTs, while resistance to injection and criteria of high BMI necessary for subsidized use of GLP-1 RAs might account for their low use in elderly patients,” commented the researchers.

By contrast, the use of DPP-4 inhibitors, known to have neutral effects on cardiovascular-renal outcomes, continued to increase similarly across all ages, including those ≥75 years.

“Despite some disconnect between guidelines and real-world practice, overall glycaemic control had improved in those 60–74 years and ≥75 years of age in the past two decades, with lower proportions of patients in the extreme HbA_1c categories [<6 percent and >9 percent] and reduction in SH from 3.4 events to 0.7 events per 100 person-years,” noted the researchers.