Lee, Douglas S.

Background Hypertensive disorders of pregnancy (HDP) are a leading global cause of maternal and fetal morbidity/mortality. Most estimates of HDP occurrence are reported for composite exposures of HDP or preeclampsia alone, with limited disaggregation by obstetrical subgroup (eg, multi‐fetal deliveries). Consequently, our understanding of HDP prevalence and temporal trends remains limited, and methods for identifying specific diagnoses in administrative data remain underexamined. This population‐based descriptive study assessed how enhanced administrative case‐finding definitions influence prevalence estimates of HDP in pregnancy and postpartum. Methods Included were individuals aged ≥18 years discharged from an Ontario hospital following their first obstetrical delivery between April 1, 2002, and December 31, 2017. We calculated overall and annual prevalence estimates and assessed temporal trends for any HDP and major subtypes by case‐finding definitions, stratified by plurality (singleton versus multi‐fetal deliveries). Results Most subjects had a singleton first delivery (n=781 258; 98%); however, HDP was 2.2 to 2.4 times more prevalent in multi‐fetal deliveries. When pre‐pregnancy hypertension was considered during case‐finding, HDP prevalence increased from 193.6 to 207.6 per 1000 multi‐fetal deliveries and from 79.9 to 92.6 per 1000 singleton deliveries. Gestational hypertension was the most common diagnosis in both populations but was nearly twice as common in those who delivered a multiple gestation (94.4–100.0 versus 49.7–53.4 per 1000 deliveries). Prevalence trends differed by coding strategy and plurality. Conclusions Although informative, data from discharge abstracts alone are insufficient for HDP surveillance, particularly for chronic hypertension in pregnancy. Validation studies should assess the accuracy of our case‐finding definitions against suitable reference standards.

OBJECTIVE Standardized, reproducible, and feasible quantification of β-cell function (BCF) is necessary for the evaluation of interventions to improve insulin secretion and important for comparison across studies. We therefore characterized the responses to, and reproducibility of, standardized methods of in vivo BCF across different glucose tolerance states. RESEARCH DESIGN AND METHODS Participants classified as having normal glucose tolerance (NGT; n = 23), prediabetes (PDM; n = 17), and type 2 diabetes mellitus (T2DM; n = 22) underwent two standardized mixed-meal tolerance tests (MMTT) and two standardized arginine stimulation tests (AST) in a test-retest paradigm and one frequently sampled intravenous glucose tolerance test (FSIGT). RESULTS From the MMTT, insulin secretion in T2DM was >86% lower compared with NGT or PDM (P < 0.001). Insulin sensitivity (Si) decreased from NGT to PDM (∼50%) to T2DM (93% lower [P < 0.001]). In the AST, insulin secretory response to arginine at basal glucose and during hyperglycemia was lower in T2DM compared with NGT and PDM (>58%; all P < 0.001). FSIGT showed decreases in both insulin secretion and Si across populations (P < 0.001), although Si did not differ significantly between PDM and T2DM populations. Reproducibility was generally good for the MMTT, with intraclass correlation coefficients (ICCs) ranging from ∼0.3 to ∼0.8 depending on population and variable. Reproducibility for the AST was very good, with ICC values >0.8 across all variables and populations. CONCLUSIONS Standardized MMTT and AST provide reproducible and complementary measures of BCF with characteristics favorable for longitudinal interventional trials use.