VIENNA – Two separate analyses of data from the Dutch-based, longitudinal Diabetes Care System cohort show that there are four distinct, but not necessarily related, subgroups of patients with type 2 diabetes based on hemoglobin A1c and systolic blood pressure over time.
Both analyses showed that, on the whole, most patients with type 2 diabetes are well controlled, with 83% hitting a European guideline–directed HbA1c target of 7% or less and 86% achieving adequate (140 mm Hg or lower) systolic blood pressure (SBP) control, both after a mean follow-up of 5.7 years.
However, there were two distinct subgroups of patients in both analyses who did not achieve good HbA1c or SBP control, with a fourth group showing a delayed response to therapy.
“This is the start of a new analysis,” said Dr. Giel Nijpels of the VU University Medical Center in Amsterdam where the research was coordinated. “We plan to do dynamic prediction models,” he added, with the aim of “more individualized prediction of patient level of risk.”
Patients with type 2 diabetes are at increased risk for both micro- and macrovascular complications, Dr. Nijpels said at the annual meeting of the European Association for the Study of Diabetes. However, “what every doctor knows, especially primary care physicians, is that not every patient with type 2 diabetes has the same risk.”
Guidelines do not take the individual characteristics into account and recommend fixed targets for both glucose and blood pressure control. These targets are based on randomized, controlled trial data, which do not reflect “real world” clinical practice, he observed. Since type 2 diabetes is a heterogeneous disease, and clearly “one size does not fit all,” there was a need to look at the trajectories of both blood glucose and blood pressure control, to see if there are any changes over time that may help to identify patients that may need a little extra help to achieve their personalized targets.
The Diabetes Care System cohort was initiated in 1998 and is a centrally organized diabetes care system. There are currently 9,849 patients with types 2 diabetes registered in the system, who were included anytime from the start of the program until 2012. Patients undergo a physical examination at recruitment and glycemic, blood pressure, and other key parameters are recorded at this baseline. Patients are then checked annually, providing a longitudinal source of real-world data.
For the analysis of blood glucose control, which Dr. Nijpels presented, patients had to have at least two HbA1c follow-up measurements; 5,423 patients were included. For the analysis of blood pressure control, presented by his college Dr. Iris Walraven, at least two SBP follow-up measurements were needed; 5,711 patients fulfilled this criteria.
The four subgroups of patients based on glycemic control were labeled “good glycemic control,” “fast responders,” “reduced glycemic control,” and “nonresponders.” There were 83.1%, 8.2%, 5.2%, and 3.4% in each group, respectively. The good glycemic control group maintained a target HbA1c of 7% or lower throughout the follow-up period, which was up to a maximum of 9 years. As the name suggests, the 8.2% of patients in the fast responders group experienced a rapid drop in HbA1c in the first 2 years of treatment, and then maintained a target HbA1c for the duration of follow-up. The 5.2% of patients with reduced glycemic control exhibited an initial HbA1c decrease very close to target, but this subsequently rose further away from the desired target during follow-up, and the 3.4% who were “nonresponders” failed to achieved a target HbA1c throughout the course of their treatment.
Analysis showed that the fast responders tended to have significantly higher HbA1c values at baseline, compared with the reduced glycemic control or nonresponsive subgroups, with comparable HbA1c to those in the “good glycemic control” subgroup. Patients in the reduced control and nonresponder subgroups tended to be younger (under 60 years of age) and have a longer diabetes duration (more than 1 year), with a higher prevalence of microvascular complications than the good or fast control groups, Dr. Nijpels reported.
In terms of treatment, most patients were “doing well” on metformin alone, sulfonylurea monotherapy, or on both of those, with about a quarter of patients using insulin.
Four subgroups of patients with distinct SBP control over time were also identified, although they were not directly linked to the four glycemic control subgroups, said Dr. Walraven in an interview. She noted that while the majority (85.6%) of patients fell into the “adequate SBP control” group, achieving a guideline-recommend systolic blood pressure of 140 mm Hg or lower, 5.6% were “delayed responders,” 3.4% were “insufficient responders,” and 3.4% were “nonresponders.”