Lower extremity complications, amputation more likely in Malays with diabetes

Ethnicity seems to play a strong role in diabetes-related lower extremity complications (DRLEC), according to a recent Singapore study. Malays, in particular, are most likely to progress to DRLEC and require an amputation.

“Differences in the pathophysiology of diabetes and its complications, burden of comorbid conditions and health service utilization may be potential reasons for the observed ethnic differences,” the researchers said. “Greater research efforts are needed to understand the aetiopathological and sociocultural processes that contribute to the higher risk of lower extremity complications among these ethnic groups.”

Drawing from Singapore’s National Healthcare Group Chronic Disease Management System, the researchers retrospectively reviewed data from 156,593 patients with incident type 2 diabetes. Incidence of, time to event, and risk factors for DRLEC were assessed.

Majority of the participants were of Chinese descent (65.2 percent; n=88,567), while 12.7 percent (n=17,303) and 13.0 percent (n=17,694) were Malay and Indian, respectively. The remaining 9.0 percent (n=12,285) were of other ethnicities. Ultimately, 19,536 participants developed DRLECs, of whom 1,208 needed an amputation. [Diabetologia 2021;doi:10.1007/s00125-021-05441-3]

Among ethnic groups, Malays saw the highest crude (32.75 per 1,000 person-years) and age- and sex-adjusted (36.09 per 1,000 person-years) incidence rates of DRLEC.

Similarly, incidence rates for amputation were highest among Malays (crude: 13.06 per 1,000 person-years; adjusted: 12.96 per 1,000 person-years). Both DRLEC and amputation were more common among men, though only DRLEC was affected by age.

The time to progression to DRLEC also tended to be shorter for Malays, men, and in some age groups. The median time to the first occurrence of DRLEC since diabetes diagnosis was 30.5 months for those who did not progress beyond DRLEC and 10.9 months for those who eventually needed amputations.

Cox proportional hazard regression analysis confirmed that the Malay ethnicity was a significant risk factor for progression to first DRLEC, increasing its risk by 29 percent (hazard ratio [HR], 1.29, 95 percent confidence interval [CI], 1.23–1.35; p<0.001). No such interaction was reported for amputation risk.

The Indian ethnicity also slightly increased DRLEC risk (HR, 1.07, 95 percent CI, 1.01–1.13; p=0.014) but significantly eased the likelihood of amputation (HR, 0.49, 95 percent CI, 0.29–0.83; p=0.007). The male sex increased the risk of both DRLEC and amputation.

“We found significant ethnic differences in the incidence of both DRLECs and amputation in our population. Southeast Asian Malays had much higher incidence of both DRLECs and amputations compared with East Asian Chinese, while there were no differences between South Asian Indians and Chinese,” the researchers said.

“[G]reater and sustained focus on improving diabetes care in general, and diabetic foot care in particular, will be needed to reduce the transition to DRLEC in this multiethnic population,” they added.