Literature describing a relationship between dietary protein intake during pregnancy and offspring insulin resistance are equivocal perhaps because of the lapse between maternal and offspring measurements (~9-40 years). Thus, we evaluated protein intake in healthy women [n = 182, mean ± SD; body mass index (BMI): 26.2 ± 4.2 kg/m2] in early pregnancy (8.4 ± 1.6 weeks, EP), late pregnancy (30.1 ± 0.4 weeks, LP), and averaged throughout pregnancy, and determined the relationship between protein intake and offspring homeostatic model assessment of insulin resistance (HOMA2-IR) at 12 (12mo) and 24 (24mo) months. EP protein (g·kg-1·day-1) did not associate with HOMA2-IR at 12mo (β = 0.153, p = 0.429) or 24mo (β = -0.349, p = 0.098). LP protein did not associate with HOMA2-IR at 12mo (β = 0.023, p = 0.916) or 24mo (β = -0.442, p = 0.085). Finally, average protein did not associate with HOMA2-IR at 12mo (β = 0.711, p = 0.05) or 24mo (β = -0.445, p = 0.294). Results remained unchanged after adjusting for plant protein intake quartiles during pregnancy, maternal BMI, and offspring sex and body fat percentage. Additionally, these relationships did not change after quartile analysis of average protein intake, even after considering offspring fasting time and HOMA2-IR outliers, and maternal under-reporters of energy intake. Protein intake during pregnancy is not associated with indirect measurements of insulin sensitivity in offspring during the first two years of life.
Keywords: HOMA-IR; glucose; insulin; insulin resistance; insulin sensitivity; obesity; offspring; plant protein; pregnancy; protein.