TY - JOUR T1 - Urinary C peptide creatinine ratio in pregnant women with normal glucose tolerance and type 1 diabetes: evidence for insulin secretion JF - BMJ Open Diabetes Research & Care JO - BMJ Open Diab Res Care DO - 10.1136/bmjdrc-2016-000313 VL - 5 IS - 1 SP - e000313 AU - Ankica Markoska AU - Rajalakshmi Valaiyapathi AU - Chloe Thorn AU - Anne Dornhorst Y1 - 2017/01/01 UR - http://drc.bmj.com/content/5/1/e000313.abstract N2 - Hypothesis In pregnancy, urinary C peptide creatinine ratio (UCPCR) reflects endogenous insulin secretion in women with normal glucose tolerance and type 1 diabetes.Research design and methods UCPCR and serum C peptide were measured in 90 glucose-tolerant women at 0 and 120 min during a 75 g oral glucose tolerance test (OGTT) at 28 weeks of gestation. UCPCR was measured in 2 samples obtained over 10 weeks apart in 7 pregnant women with longstanding type 1 diabetes.Results UCPCROGTT and serum C peptideOGTT of glucose-tolerant women were significantly correlated at 0 and 120 min (rs0.675, 0.541 respectively, p<0.0001). All 7 pregnant women with type 1 diabetes had detectable first sample UCPCR (median (range) 49 (6–1038) pmol/mmol) that rose in 6 women by 477 (29–1491) pmol/mmol.Conclusions Detectable UCPCR in pregnant women with normal glucose tolerance and type 1 diabetes is likely to reflect endogenous insulin secretion and hence β-cell activity. ER -