Risk of DR, DME in T2DM significantly higher with combined diabetes control indicators
The risks of diabetic macular oedema (DME) and diabetic retinopathy (DR) were three to four times higher in type 2 diabetes (T2DM) cases assessed with combinations of indicators than with individual indicators, a new cross-sectional study shows.
This suggests that targeting combined diabetes control indicators is important in reducing the risk of DR or DME, the investigators said.
The study included 613 T2DM patients (mean age 66.0±10.5 years; 57 percent male) from the Australian Diabetes Management Project. None of the patients had significant cognitive and hearing impairments. Fast macular scans with retinal map analyses and two-field dilated fundus photography were used to assess DME and DR, respectively.
Individual indicators for diabetes control were glycaemic control, blood pressure (BP) control and lipid control. The combinations of these indicators that were used in the study were glycaemic and BP control, glycaemic and lipid control, BP and lipid control, and glycaemic, BP and lipid control.
Of all the participants, 60.1 percent (n=372) had DR while 30.5 percent (n=181) had DME. Of the DR patients, 57.3 percent (n=213) had mild-to-moderate nonproliferative DR (NPDR) while the remaining 42.7 percent (n=159) had severe NPDR/PDR. [PLoS One 2017;doi:10.1371/journal.pone.0180252]
Patients with DR were significantly more likely to use insulin (p<0.001), have at least one diabetes-related complication (p<0.001) and have longer duration of diabetes (p<0.001).
Poor glucose control was reported in 31.9 percent of the study sample, while poor BP and lipid control was reported in 6.8 and 5.4 percent, respectively. For the combined indicators, 13.1 percent had poor glucose and BP control, 13.1 percent had poor glucose and lipid control, 2.6 percent had poor BP and lipid control, and 8.9 percent had poor glucose, lipid and BP control.
The risk of DR was significantly higher in participants with poor glucose control only (odds ratio [OR], 2.44; 95 percent CI, 1.34 to 4.46; p=0.004) than in those with three indicators of good control.
Similarly, those with poor glucose and lipid control (OR, 3.75; 1.75 to 8.07; p=0.001), poor glucose and BP control (OR, 4.64; 2.13 to 10.12; p<0.001), and poor glucose, lipid and BP control (OR, 2.28; 1.01 to 5.16; p=0.047) had significantly higher DR risks compared with those with indicators of good control.
On the other hand, the risk of DME was significantly higher in those with poor glucose control only vs individuals with all three indicators of good control (OR, 3.19; 1.55 to 6.59; p=0.004).
Those with poor glucose and BP control (OR, 2.76; 1.18 to 6.44; p=0.019), poor glucose and lipid control (OR, 3.60; 1.58 to 8.22; p=0.002), and poor glucose, lipid and BP control (OR, 3.01; 1.18 to 7.67; p=0.021) also had significantly higher risks of DME compared with individuals with indicators of good control.
Interestingly, the differences between ORs for DR and DME in those with poor glucose control only (2.44 and 3.19, respectively) and those with poor glucose and lipid control (3.75 and 3.60) were statistically significant (p=0.001 and p=0.004, respectively). This trend was also observed for individuals with poor glucose and BP control.
“Overall, these data suggest there is a significant increase in odds of DR for a patient with poor lipid or poor BP control in addition to poor glucose control, compared to just glucose control alone. In contrast, poor BP control alone, poor lipid control alone, and poor BP and lipid control combined were not independently associated with increased odds of DR,” the investigators wrote.