Annemarie Wentzel, Ph.D., MSc

Photo of Dr. Annemarie Wentzel

Postdoctoral Fellow

National Institute of Diabetes and Digestive and Kidney Diseases

The Effect of Psychosocial and Physiologic Stress on the Development of β Cell Failure in African Immigrants with Abnormal Glucose Tolerance

Abnormal glucose tolerance (Abnl-GT) combines diabetes and prediabetes into a single term and occurs due to an imbalance between insulin resistance (IR) and β-cell function. In African American individuals, Abnl-GT is most often due to IR-related obesity. However, data emerging from the Africans in America cohort reveals that the majority of African immigrants with Abnl-GT are nonobese and have β-cell-failure. Most nonobese individuals are not identified as “at-risk” – consequently, they are usually diagnosed only after the onset of clinical complications. Hence, preventable disease progression occurs due to late diagnosis of Abnl-GT-β-cell-failure. Yet, knowledge on β-cell-failure as the primary determinant of Abnl-GT is lacking. The psychosocial precipitants, phenotype and optimal tests to detect β-cell-failure in African immigrants are also undetermined. The application of adiponectin and copeptin as markers of β-cell-failure have also never been assessed in African populations.

Working with African immigrants, Dr. Wentzel and her team’s primary goal is to assess the metabolic consequences in the Abnl-GT-β-cell-failure group vs NGT, and to examine and compare the psychosocial and physiological stress precipitants in the Abnl-GT-β-cell-failure group first to the NGT and then to the Abnl-GT-IR group.

Glucose tolerance will be determined by oral glucose tolerance test. Abnl-GT is defined as fasting glucose≥100 mg/dL and/or 2h glucose≥140 mg/dL. Insulin resistance (IR) will be determined by the lowest quartile of the Matsuda index. Abnl-GT-IR requires both Abnl-GT and IR. Abnl-GT-β-cell failure requires Abnl-GT without IR. Psychosocial and physiologic stress measures will include: Cohen Perceived Stress Scale, allostatic load score, acculturation, and sleep quality. Plasma adiponectin and copeptin levels will also be measured.

If the psychosocial and metabolic profiles are worse in Abnl-GT-β-cell-failure than the NGT group, this will reveal a previously unappreciated public health problem. Risk underestimation in the Abnl-GT-β-cell-failure means diagnosis only after the onset of clinical complications. If adiponectin and copeptin prove useful within the context of Abnl-GT-β-cell-failure in African immigrants, their application across African populations could provide diagnostic and mechanistic insight regarding Abnl-GT-β-cell-failure, and the psychosocial stress-linked to β-cell-failure.

Page updated December 8, 2021