In low and middle-income countries in Africa, β-cell-failure in the absence of obesity is increasingly recognized as a frequent cause of type 2 diabetes (DM) . DM risk scores assume that insulin resistance (IR) is the primary cause of DM. Therefore, their ability to detect DM due to β-cell-failure is unknown. In 529 African-born Blacks living in the United States (age 38± (mean±SD) ; 64% male; BMI 28±5 kg/m2) , we assessed (1) DM prevalence, (2) prevalence of DM due to IR versus β-cell failure; and (3) the ability of six risk scores (Cambridge, FINDRISC, Kuwaiti, Omani, Rotterdam, and SUNSET) to detect previously undiagnosed DM due to either IR or β-cell-failure. DM was diagnosed by OGTT and/or HbA1c ≥6.5%. IR was defined by lowest quartile of the Matsuda index (≤2.04) . DM due to β-cell-failure required DM in the absence of IR. Data on BP, BMI, waist circumference (WC) , health behaviors, and medical history were collected. Area under the Receiver Operator Characteristics Curve (AROC) assessed discriminatory ability of each score. Criteria for AROC: no discrimination=0.50; poor=0.50-0.69; acceptable=0.70-0.79; excellent=0.80-0.89; outstanding=≥0.90. DM prevalence was 9% (46/529) . DM was due to IR in 57% (26/46) and β-cell-failure in 44% (20/46) . The IR group had higher BMI (31±5 vs. 27±4 kg/m2 P<0.001) , and higher WC (101±vs. 91±cm P<0.001) . Scores had poor to excellent detection of diabetes due to IR (AROC=0.67-0.81) . In contrast, detection of diabetes due to β-cell-failure had an AROC score in the range of no discrimination or poor (AROC=0.49-0.62) .

In summary, DM risk scores perform well for the detection of undiagnosed DM in Africans when the etiology is IR. However, scores fail to detect DM due to β-cell failure. Therefore, scores which evaluate DM risk when the cause is β-cell failure are urgently needed.


A.Wentzel: None. A.Patterson: None. M.Duhuze-karera: None. Z.C.Waldman: None. B.R.Schenk: None. L.Mabundo: None. C.Dubose: None. A.E.Sumner: None. M.F.Horlyck-romanovsky: None.

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