Glycemic Control and Quality of Life in Patients With Type 2 Diabetes

To the Editor: The article by Drs Testa and Simonson¹ on health outcomes during improved glycemic control had some interesting, unexplained findings that raise the question of a negative impact of the trial on the placebo group. The percentage of employed patients who missed 0.5 or more days of work increased from 2.4% at baseline to 10.5% at the end of week 15 in the placebo group, compared with a decrease of 5.6% to 4.8% in the treated group. Per 500 days worked, the total days absent increased from 4.2 to 24 in the placebo group and decreased from 9.4 to 5.0 in the treated group. Bed-days (rates per 1000 person-days) had the same pattern: 921 at baseline to 1843 at the end of week 15 in the placebo group and 1653 to 1539 in the treated group. Most of the benefit attributed to improved glycemic control occurred because of worsening in the placebo group. Also, the placebo group had a decline in cognitive function, general perceived health, and symptom distress, while the degree of glycemic control remained the same. The authors suggest this indicates a cumulative effect of poor glycemic control on quality of life. Such an outcome might have occurred because more patients in the control group were newly diagnosed with diabetes. The duration of diabetes appeared to be the same in both groups and seemed to indicate that the number of patients with a new diagnosis of diabetes would have been the same in both groups.