Health behaviour changes in partners of women with recent gestational diabetes: a phase IIa trial.

BACKGROUND: We recently demonstrated that a gestational diabetes history in mothers is associated with higher postpartum incident diabetes not only in mothers but also in fathers. In the present study, we examined changes in health behaviours and cardiometabolic profiles in both mothers and partners who participated in a diabetes prevention program within 5 years of a gestational diabetes pregnancy. METHODS: Couples were enrolled into a 13-week program that included 5 half-day group sessions and web/telephone-based support between sessions. It was designed in consultation with patients and previously studied in mothers. We computed mean changes from baseline (95% CI) for physical activity, eating, and sleep measures, and cardiometabolic parameters (fasting and 2-h post glucose load plasma glucose, BMI, blood pressure) in both partners and mothers. RESULTS: Among 59 couples enrolled, 45 partners (76%) and 47 mothers (80%) completed final evaluations. Baseline cardiometabolic measures averaged within normal limits. Similar to mothers, partners increased physical activity (+ 1645 steps/day, 95%CI 730, 2561; accelerometer assessed moderate-to-vigorous physical activity + 36.4 min/week, 95% CI 1.4, 71.4) and sleep duration (+ 0.5 h/night, 95% CI 0.1, 0.9) and reduced the sodium-to-potassium ratio of food intake (- 0.09 95% CI -0.19, - 0.001). No conclusive changes were observed in glucose measures or insulin resistance; in analyses combining mothers and partners, systolic blood pressure decreased (- 2.7 mmHg, 95% CI -4.4, - 1.0). CONCLUSIONS: Partners and mothers demonstrated improved physical activity, sleep, and dietary quality. Baseline cardiometabolic profiles averaged at normal values and there were no changes in glucose or insulin resistance; some blood pressure impact was observed. While strategies need to be developed to attract participants at higher cardiometabolic risk, this study demonstrates that partners of women within 5 years of a gestational diabetes diagnosis can be recruited and do achieve health behaviour change. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02343354 (date of registration: January 22, 2015).

Group-based activities with on-site childcare and online support improve glucose tolerance in women within 5 years of gestational diabetes pregnancy.

BACKGROUND: Women with gestational diabetes history are at increased risk for type 2 diabetes. They face specific challenges for behavioural changes, including childcare responsibilities. The aim of this study is to test a tailored type 2 diabetes prevention intervention in women within 5 years of a pregnancy with gestational diabetes, in terms of effects on weight and cardiometabolic risk factors. METHODS: The 13-week intervention, designed based on focus group discussions, included four group sessions, two with spousal participation and all with on-site childcare. Web/telephone-based support was provided between sessions. We computed mean percentage change from baseline (95% confidence intervals, CI) for anthropometric measures, glucose tolerance (75 g Oral glucose tolerance test), insulin resistance/sensitivity, blood pressure, physical activity, dietary intake, and other cardiometabolic risk factors. RESULTS: Among the 36 enrolled, 27 completed final evaluations. Most attended ≥ 3 sessions (74%), used on-site childcare (88%), and logged onto the website (85%). Steps/day (733 steps, 95% CI 85, 1391) and fruit/vegetable intake (1.5 servings/day, 95% CI 0.3, 2.8) increased. Proportions decreased for convenience meal consumption (-30%, 95% CI -50, -9) and eating out (-22%, 95% CI -44, -0) ≥ 3 times/month. Body mass index and body composition were unchanged. Fasting (-4.9%, 95% CI -9.5, -0.3) and 2-hour postchallenge (-8.0%, 95% CI -15.6, -0.5) glucose declined. Insulin sensitivity increased (ISI 0,120 23.7%, 95% CI 9.1, 38.4; Matsuda index 37.5%, 95% CI 3.5, 72.4). Insulin resistance (HOMA-IR -9.4%, 95% CI -18.6, -0.1) and systolic blood pressure (-3.3%, 95% CI -5.8, -0.8) decreased. CONCLUSIONS: A tailored group intervention appears to lead to improvements in health behaviours and cardiometabolic risk factors despite unchanged body mass index and body composition. This approach merits further study. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT01814995).

The predictive ability of conditional fetal growth percentiles.

Conditional fetal growth percentiles are percentiles that are calculated taking into account (conditional on) an infant's weight earlier in pregnancy. Although they have been proposed in the statistical literature as a more methodologically appropriate method of measuring fetal growth, their ability to predict adverse perinatal outcomes due to fetal growth restriction is unknown. Using a large, unselected clinical ultrasound database at the Royal Victoria Hospital in Montreal, Canada, we calculated conditional growth percentiles for infants' weight at birth, given their weight at the time of a routine 32- or 33-week ultrasound. The risk of adverse perinatal outcome (perinatal mortality, low Apgar, acidaemia, or seizures/organ failure due to asphyxia) among small-for-gestational-age infants (SGA) as established by conditional growth percentiles was calculated as well as the risk among infants classified as SGA by conventional weight-for-gestational-age percentiles. Regardless of the threshold used to define SGA (fifth, 10th, 15th, 20th), conditional percentiles did not appear to improve the identification of adverse perinatal outcomes compared with conventional weight-for-gestational-age charts. Further work is needed to confirm our results as well as to explore potential reasons for the lack of benefits from using a measure of growth instead of size to identify fetal growth restriction.

A Pilot Randomized-Controlled Trial on the Effect of CPAP Treatment on Glycemic Control in Gestational Diabetes: Study Design and Methods.

Background: Gestational diabetes (GDM) is associated with adverse short- and long-term maternal and fetal outcomes. Observational data support a link between sleep-disordered breathing (SDB) during pregnancy and GDM. However, it is unknown whether treatment of SDB with continuous positive airway pressure (CPAP) improves glucose control in this patient population. In addition, CPAP adherence and feasibility as a treatment option in pregnancy is unknown. This pilot randomized, controlled trial aims to primarily determine the feasibility of CPAP treatment in pregnant women with SDB and GDM. This study is also investigating the effect of SDB treatment on 24-h glucose profiles as an exploratory outcome. Objectives: To describe the study methodology in this ongoing study of pregnant women with GDM and SDB. Patients and Methods: Pregnant women with GDM and SDB defined by apnea-hypopnea index (AHI) ≥10 (Chicago Scoring Criteria) on level 2 polysomnography are randomized to either auto titrating CPAP (experimental group) or a nasal dilator strip (control group) until delivery. The primary outcome, objectively-assessed adherence to CPAP, is measured over the course of the treatment period using device-specific software. Recruitment and retention rates will be calculated to assess the feasibility for planning future trials. Twenty-four hour glucose profiles are measured over a 72-h period using the continuous glucose monitoring (CGM) system, before and after the intervention. Conclusion: The results of this study will be highly informative to determine whether CPAP is a feasible treatment for pregnant women with GDM and SDB, a specialized population at risk for substantial comorbidity. The trial results will ultimately be useful in planning future SDB treatment trials in pregnancy and GDM. The study is registered on clinicaltrials.gov (NCT02245659).

Research Gaps in Gestational Diabetes Mellitus: Executive Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop.

The National Institute of Diabetes and Digestive and Kidney Diseases convened a workshop on research gaps in gestational diabetes mellitus (GDM) with a focus on 1) early pregnancy diagnosis and treatment and 2) pharmacologic treatment strategies. This article summarizes the proceedings of the workshop. In early pregnancy, the appropriate diagnostic criteria for the diagnosis of GDM remain poorly defined, and an effect of early diagnosis and treatment on the risk of adverse outcomes has not been demonstrated. Despite many small randomized controlled trials of glucose-lowering medication treatment in GDM, our understanding of medication management of GDM is incomplete as evidenced by discrepancies among professional society treatment guidelines. The comparative effectiveness of insulin, metformin, and glyburide remains uncertain, particularly with respect to long-term outcomes. Additional topics in need of further research identified by workshop participants included phenotypic heterogeneity in GDM and novel and individualized treatment approaches. Further research on these topics is likely to improve our understanding of the pathophysiology and treatment of GDM to improve both short- and long-term outcomes for mothers and their children.

Is birth weight modified during pregnancy? Using sibling differences to understand the impact of blood glucose, obesity, and maternal weight gain in gestational diabetes.

OBJECTIVE: The purpose of this study was to examine the extent to which blood glucose, obesity, and maternal weight gain explains differences in birth weight using offspring sibling pairs in gestational diabetes mellitus (GDM). STUDY DESIGN: A retrospective analysis of 90 women with at least 2 GDM pregnancies was conducted. A fixed effects model was used to examine differences between siblings of the same mother (within-women), and results were contrasted with a multivariable regression model that compared different mothers (between-women). RESULTS: Higher maternal weight gain was significantly associated with increased birth weight within mothers, but not between different women. Conversely, overweight status (body mass index [BMI] > or = 25) was significant between-mothers, but not within an individual mother's pregnancies. One-hour postprandial glucose was significant between-mothers, with a weaker association within-mothers. There was no association between fasting glucose and birth weight in either analysis. CONCLUSION: Controlling pregnancy weight gain may reduce offspring birth weight in individual women with GDM, while the association between high birth weight and elevated prepregnancy BMI may represent a predisposition to both characteristics.

The importance of a postpartum 75 g oral glucose tolerance test in women with gestational diabetes.

OBJECTIVE: To compare the ability of the fasting plasma glucose (FPG) level with the ability of the 2-hour oral glucose tolerance test (OGTT) to identify women with any form of glucose intolerance within the first six postpartum months. METHODS: In a retrospective, observational analysis, the predictive ability of the FPG level was compared with that of the 2-hour OGTT in 275 women followed for gestational diabetes who returned for postpartum testing. RESULTS: With use of the FPG level alone, 4.4% of the women were found to have an FPG 7.0 mmol/L, identifying diabetes mellitus (DM); 2.5% had an FPG in the range 6.1-6.9 mmol/L, identifying impaired fasting glucose (IFG); and 93% had an FPG 6.0 mmol/L, i.e., within the normal range. Using the 2-hour 75g OGTT, 5% of women were found to have either an FPG 7.0 mmol/L or a 2-hour plasma glucose (PG) 11.1 mmol/L, identifying DM; 2.5% had an FPG of 6.1-6.9 mmol/L, identifying IFG; and 32% had a 2-hour PG of 7.8-11.0 mmol/L, identifying impaired glucose tolerance (IGT). Of the women with any glucose abnormality postpartum, an FPG level alone detected 15.8%, the post-glucose load level detected 97.5%, and an OGTT detected 100% of the women. An FPG level alone in 39% of cases failed to detect either IGT or DM and in 54% of cases, type 2 DM. CONCLUSION: In view of the potential for early, effective prevention of DM, the optimal method for detecting glucose abnormalities in women within six months post partum is a 2-hour OGTT.

Strategies for implementing the WHO diagnostic criteria and classification of hyperglycaemia first detected in pregnancy.

The World Health Organization (WHO) has recently released updated recommendations on Diagnostic Criteria and Classification of Hyperglycaemia First Detected in Pregnancy which are likely to increase the prevalence of gestational diabetes mellitus (GDM). Any increase in the number of women with GDM has implications for health services since these women will require treatment and regular surveillance during the pregnancy. Some health services throughout the world may have difficulty meeting these demands since country resources for addressing the diabetes burden are finite and resource allocation must be prioritised by balancing the need to improve care of people with diabetes and finding those with undiagnosed diabetes, including GDM. Consequently each health service will need to assess their burden of hyperglycaemia in pregnancy and decide if and how it will implement programmes to test for and treat such women. This paper discusses some considerations and options to assist countries, health services and health professionals in these deliberations.

Gestational glucose intolerance modifies the association between magnesium and glycemic variables in mothers and daughters 15 years post-partum.

BACKGROUND: Gestational diabetes mellitus (GDM) and low magnesium (Mg) intake and status are associated with an increased risk of type 2 diabetes. However, Mg homeostasis may be modified by GDM. We sought to determine if a history of GDM prospectively modifies associations between Mg and glycemic variables in mothers and their offspring. METHODS: Plasma and dietary Mg, anthropometric, lifestyle and glycemic variables were assessed in mothers affected by GDM during 1989-1990, a comparative group of normoglycemic women, pregnant during the same time period, and the 15-year-old, nondiabetic daughters of affected and unaffected pregnancies (n = 332). Multivariate regression analyses evaluated the cross-sectional association between plasma and dietary Mg with glycemic variables in mothers and daughters. RESULTS: Plasma Mg was lower in mothers with a history of GDM in comparison to control mothers after adjustment for current type 2 diabetes, race and body mass index (0.90 ± 0.01 versus 0.96 ± 0.01 mmol/L; p = 0.002). Plasma Mg was significantly associated with insulin sensitivity and was inversely associated with fasting insulin in GDM mothers only (p<0.05). Plasma and dietary Mg were significantly inversely associated with glycated hemoglobin and fasting glucose, respectively, in nondiabetic teenage daughters. For fasting glucose, plasma Mg was inversely associated in GDM-born daughters only. CONCLUSIONS: Associations between plasma Mg and some glycemic variables may be stronger in mothers and offspring with a history of GDM.

The association of desaturase 9 and plasma fatty acid composition with insulin resistance-associated factors in female adolescents.

Desaturase 9 (Delta 9), which converts saturated fatty acids (SFAs) into monounsaturated fatty acids, is an important component in leptin-mediated energy homeostasis in rodent models. Few human studies, however, have been performed regarding the clinical relevance of Delta 9, particularly whether Delta 9 is involved in the relationship between blood fatty acid profiles and insulin resistance-associated factors. The aim of the present study was to examine fatty acid data from 178 apparently healthy female adolescents and determine whether (a) Delta 9 has independent associations with adiposity, insulin resistance level, and fasting plasma polyunsaturated fatty acids (PUFAs); (b) Delta 9 is a predictor of fasting blood lipid profile; and (c) the associations between fasting plasma fatty acid component and insulin resistance level are independent of abdominal obesity level. Desaturase 9-16 (surrogate of Delta 9 as calculated by plasma ratio C16:1 n-7/C16:0) correlated with waist girth (r = .160, P < .05), homeostasis model assessment of insulin resistance (HOMA-IR) (r = .201, P < .01), plasma PUFAs (eg, C20:4 n-6 [r = -.269, P < .001], C22:6 n-3 [r = -.274, P < .001]). After adjustment for dietary SFAs, Delta 9-16 had stronger correlation with waist (r = .227, P < .01) and significant correlation with PUFAs, whereas it had a nonsignificant correlation with HOMA-IR. The same pattern was observed with Delta 9-18 (surrogate of Delta 9 as calculated by plasma ratio C18:1 n-9/C18:0). After adjustment for dietary SFAs, waist, and HOMA-IR, Delta 9-16 and Delta 9-18 were still positive predictors of triglyceride (both P < .001) and apolipoprotein B (Delta 9-18, P < .001; Delta 9-16, P = .052). After adjustment for waist, HOMA-IR only remained a positive determinant of medium-chain SFAs (C14:0, P < .001; C16:0, P < .05); but it emerged to be inversely related to C20:4 n-6 (P < 0.1). The positive and independent associations of medium-chain SFAs with insulin resistance level suggest their vital roles in diabetes pathogenesis, whereas certain PUFAs such as C20:4 n-6 appear to be protective. The observed associations of Delta 9 with adiposity and plasma lipid profile in these apparently healthy female adolescents support the concept derived from rodent models that Delta 9 activity is independently reflective of higher body mass index and higher circulatory triglyceride levels.