Postpartum weight retention and the early evolution of cardiovascular risk over the first 5 years after pregnancy.

BACKGROUND: The cumulative effect of postpartum weight retention from each pregnancy in a woman's life may contribute to her risk of ultimately developing type 2 diabetes and cardiovascular disease. However, there is limited direct evidence supporting this hypothesis. Thus, we sought to characterize the impact of postpartum weight retention on the trajectories of cardiovascular risk factors over the first 5-years after pregnancy. METHODS: In this prospective observational cohort study, 330 women (mean age 35.7 ± 4.3 years, mean pre-pregnancy body mass index 25.2 ± 4.8 kg/m2, 50.9% primiparous) underwent serial cardiometabolic characterization (anthropometry, blood pressure, lipids, oral glucose tolerance test, insulin sensitivity/resistance (Matsuda index, HOMA-IR), C-reactive protein (CRP), adiponectin) at 1-year, 3-years, and 5-years postpartum. Based on the magnitude of weight change between pre-pregnancy and 5-years postpartum, they were stratified into the following 3 groups: weight loss (n = 100), weight gain 0-6% (n = 110), and weight gain ≥ 6% (n = 120). RESULTS: At 1-year postpartum, cardiovascular risk factors did not differ between the groups. However, an adverse risk factor profile progressively emerged in the weight retention groups at 3- and 5-years. Indeed, after covariate adjustment, there was stepwise worsening (from the weight loss group to weight gain 0-6% to weight gain ≥ 6% group) of the following cardiovascular risk factors at 5-years: triglycerides (p = 0.001), HDL (p = 0.02), LDL (p = 0.01), apolipoprotein-B (p = 0.003), Matsuda index (p < 0.0001), HOMA-IR (p < 0.0001), fasting glucose (p = 0.07), and CRP (p = 0.01). Moreover, on logistic regression analyses, weight gain ≥ 6% emerged as an independent predictor of pre-diabetes/diabetes at 5-years (adjusted OR = 3.40, 95%CI: 1.63-7.09). CONCLUSION: Postpartum weight retention predicts trajectories of worsening cardiovascular risk factors and glucose intolerance over the first 5-years after delivery, consistent with its postulated contribution to future vascular disease in women.

Impact of the diagnosis of gestational diabetes on maternal physical activity after pregnancy.

AIM: The diagnosis of gestational diabetes (GDM) identifies women who are at future risk of developing type 2 diabetes. However, it is unclear if diagnosing GDM thus motivates women to increase physical activity after pregnancy or if this medicalization has the opposite effect of decreasing activity, possibly reflecting assumption of a sick role. We thus sought to evaluate the impact of diagnosing GDM on changes in maternal physical activity after pregnancy. METHODS: In this prospective cohort study, physical activity patterns were assessed by the Baecke questionnaire for the year before pregnancy and the first year postpartum in 405 white women comprising the following three gestational glucose tolerance groups: (a) those who did not have GDM (non-GDM; n = 247), (b) women with undiagnosed GDM (n = 46) and (c) those diagnosed with GDM (n = 112). RESULTS: In the year before pregnancy, mean adjusted total physical activity progressively decreased from non-GDM to undiagnosed GDM to diagnosed GDM (p = .067). Conversely, at 1 year postpartum, total physical activity was highest in those who had been diagnosed with GDM (p = .02). Compared with non-GDM, diagnosed GDM predicted an increase in total physical activity from pre-pregnancy to 1 year postpartum (t = 2.3, p = .02) whereas undiagnosed GDM predicted a concurrent decrease in leisure-time activity (t = -2.74, p = .006). Accordingly, the mean adjusted increase in body mass index from pre-pregnancy to 1 year postpartum was lowest in those with diagnosed GDM (0.26 ± 0.25 kg/m2 ), highest in undiagnosed GDM (1.23 ± 0.38 kg/m2 ) and intermediate in non-GDM (0.89 ± 0.22 kg/m2 ) (overall p = .04). CONCLUSION: Diagnosis of GDM leads to increased physical activity after pregnancy that may partially attenuate postpartum weight retention.

Deteriorating beta cell function is the dominant determinant of progression from normal glucose tolerance to prediabetes/diabetes in young women following pregnancy.

AIMS/HYPOTHESIS: Excess adiposity, insulin resistance and beta cell dysfunction each contribute to the development of prediabetes (impaired glucose tolerance and/or impaired fasting glucose)/diabetes but their comparative impact in relation to one another remains uncertain. We thus ranked their contributions to incident dysglycaemia over the first 5 years postpartum in women reflecting the full spectrum of gestational glucose tolerance (spanning normoglycaemia to gestational diabetes) and hence a range of future diabetic risk. METHODS: In this study, 302 women with normal glucose tolerance (NGT) on OGTT at 3 months postpartum underwent repeat OGTT at 1 year, 3 years and 5 years, enabling serial assessment of glucose tolerance, insulin sensitivity/resistance (Matsuda index, HOMA-IR) and beta cell function (insulin secretion-sensitivity index-2 [ISSI-2], insulinogenic index [IGI]/HOMA-IR). Determinants of prediabetes/diabetes were ranked by change in concordance index (CCI) of Cox proportional hazard regression models. RESULTS: Over 5 years of follow-up, 89 women progressed from NGT to prediabetes/diabetes (progressors). At 3 months postpartum, though all women were normoglycaemic, future progressors had higher fasting glucose (p=0.03) and 2 h glucose (p<0.0001) than non-progressors, coupled with higher BMI (p=0.001), greater insulin resistance (both Matsuda index and HOMA-IR, p≤0.02) and poorer beta cell function (both ISSI-2 and IGI/HOMA-IR, p≤0.006). Unlike their peers, progressors exhibited deteriorating beta cell function from 1 year to 5 years (both p<0.0001). On regression analyses, the dominant determinants of progression to prediabetes/diabetes were time-varying ISSI-2 (change in CCI 25.2%) and IGI/HOMA-IR (13.0%), in contrast to time-varying Matsuda index (2.9%) and HOMA-IR (0.5%). Neither time-varying BMI nor waist were significant predictors after adjustment for beta cell function and insulin sensitivity/resistance. CONCLUSION/INTERPRETATION: Declining beta cell function is the dominant determinant of incident prediabetes/diabetes in young women following pregnancy.

Polymorphisms in the stearoyl-CoA desaturase gene modify blood glucose response to dietary oils varying in MUFA content in adults with obesity.

Diets varying in SFA and MUFA content can impact glycaemic control; however, whether underlying differences in genetic make-up can influence blood glucose responses to these dietary fatty acids is unknown. We examined the impact of dietary oils varying in SFA/MUFA content on changes in blood glucose levels (primary outcome) and whether these changes were modified by variants in the stearoyl-CoA desaturase (SCD) gene (secondary outcome). Obese men and women participating in the randomised, crossover, isoenergetic, controlled-feeding Canola Oil Multicenter Intervention Trial II consumed three dietary oils for 6 weeks, with washout periods of ˜6 weeks between each treatment. Diets studied included a high SFA/low MUFA Control oil (36·6 % SFA/28·2 % MUFA), a conventional canola oil (6·2 % SFA/63·1 % MUFA) and a high-oleic acid canola oil (5·8 % SFA/74·7 % MUFA). No differences in fasting blood glucose were observed following the consumption of the dietary oils. However, when stratified by SCD genotypes, significant SNP-by-treatment interactions on blood glucose response were found with additive models for rs1502593 (P = 0·01), rs3071 (P = 0·02) and rs522951 (P = 0·03). The interaction for rs3071 remained significant (P = 0·005) when analysed with a recessive model, where individuals carrying the CC genotype showed an increase (0·14 (sem 0·09) mmol/l) in blood glucose levels with the Control oil diet, but reductions in blood glucose with both MUFA oil diets. Individuals carrying the AA and AC genotypes experienced reductions in blood glucose in response to all three oils. These findings identify a potential new target for personalised nutrition approaches aimed at improving glycaemic control.

Assessments of right ventricular strain using cardiac magnetic resonance imaging following kidney transplantation.

Although kidney transplantation (KT) has been shown to ameliorate adverse left ventricular (LV) remodelling associated with end stage kidney disease, its effects on the right ventricle have not been well studied. Recently, strain imaging has been shown to be a sensitive measure of early subclinical myocardial dysfunction. Using cardiac magnetic resonance imaging (MRI), we examined the effects of KT on right ventricular (RV) strain parameters. In a cohort of 81 patients (39 patients underwent KT and 42 patients remained on dialysis as control group), cardiac MRI studies were obtained at baseline and at 1 year follow-up. There were no significant differences in RV strain values between the groups at baseline. After 1 year, RV strain values did not significantly change in patients who received KT, and changes in RV strain over 1 year were not significantly different between the KT and the dialysis groups. Given the previously demonstrated improvement in LV strain post-KT, the current study suggests that RV and LV remodelling post-KT may have different mechanisms. Further studies elucidating the effects of KT on RV remodelling are needed.

Serum apoA1 (Apolipoprotein A-1), Insulin Resistance, and the Risk of Gestational Diabetes Mellitus in Human Pregnancy-Brief Report.

OBJECTIVE: apoA1 (apolipoprotein A-1) is the main lipoprotein associated with HDL (high-density lipoprotein) cholesterol. It was recently reported that intravenous infusion of apoA1 could lower insulin resistance in pregnant rats, leading to the suggestion that apoA1 could provide a target for reducing pregnancy-induced insulin resistance and the risk of gestational diabetes mellitus (GDM) in humans. However, the effects of apoA1 on insulin resistance and risk of GDM in human pregnancy are not known. Thus, we sought to systematically evaluate the relationships of apoA1 with glucose homeostasis and metabolic function in pregnant women. Approach and Results: In this study, 870 pregnant women were recruited in late second trimester and underwent metabolic characterization, including an oral glucose tolerance test on which 214 were diagnosed with GDM. Metabolic characterization included assessment of glucose tolerance, insulin sensitivity/resistance (Matsuda index, homeostasis model assessment of insulin resistance), pancreatic ß-cell function, lipids (LDL [low-density lipoprotein] cholesterol, HDL cholesterol, triglycerides, apoB [apolipoprotein B], and apoA1), CRP (C-reactive protein), and adiponectin. Serum apoA1 was strongly correlated with HDL (r=0.79, P<0.0001) and weakly so with adiponectin (r=0.12, P=0.0004) but showed no association with measures of insulin sensitivity/resistance, ß-cell function, glycemia, or CRP. There were no significant differences across apoA1 tertiles in mean adjusted Matsuda index (P=0.24), homeostasis model assessment of insulin resistance (P=0.08), or area under the glucose curve on the oral glucose tolerance test (P=0.96). Moreover, there were no differences in risk of GDM across tertiles of apoA1, both before (P=0.67) and after covariate adjustment (P=0.78). CONCLUSIONS: Serum apoA1 is not associated with insulin resistance or the risk of GDM in human pregnancy.

Common Variants in Lipid Metabolism-Related Genes Associate with Fat Mass Changes in Response to Dietary Monounsaturated Fatty Acids in Adults with Abdominal Obesity.

BACKGROUND: Different fatty acids (FAs) can vary in their obesogenic effect, and genetic makeup can contribute to fat deposition in response to dietary FA composition. However, the antiobesogenic effects of the interactions between dietary MUFAs and genetics have scarcely been tested in intervention studies. OBJECTIVE: We evaluated the overall (primary outcome) and genetically modulated (secondary outcome) response in body weight and fat mass to different levels of MUFA consumption. METHODS: In the Canola Oil Multicenter Intervention Trial II, a randomized, crossover, isocaloric, controlled-feeding multicenter trial, 44 men and 71 women with a mean age of 44 y and an increased waist circumference (men ∼108 cm and women ∼102 cm) consumed each of 3 oils for 6 wk, separated by four 12-wk washout periods. Oils included 2 high-MUFA oils-conventional canola and high-oleic canola (<7% SFAs, >65% MUFAs)-and 1 low-MUFA/high-SFA oil blend (40.2% SFAs, 22.0% MUFAs). Body fat was measured using DXA. Five candidate single-nucleotide polymorphisms (SNPs) were genotyped using qualitative PCR. Data were analyzed using a repeated measures mixed model. RESULTS: No significant differences were observed in adiposity measures following the consumption of either high-MUFA diet compared with the low-MUFA/high-SFA treatment. However, when stratified by genotype, 3 SNPs within lipoprotein lipase (LPL), adiponectin, and apoE genes influenced, separately, fat mass changes in response to treatment (n = 101). Mainly, the LPL rs13702-CC genotype was associated with lower visceral fat (high-MUFA: -216.2 ± 58.6 g; low-MUFA: 17.2 ± 81.1 g; P = 0.017) and android fat mass (high-MUFA: -267.3 ± 76.4 g; low-MUFA: -21.7 ± 102.2 g; P = 0.037) following average consumption of the 2 high-MUFA diets. CONCLUSIONS: Common variants in LPL, adiponectin, and apoE genes modulated body fat mass response to dietary MUFAs in an isocaloric diet in adults with abdominal obesity. These findings might eventually help in developing personalized dietary recommendations for weight control. The trial was registered at clinicaltrials.gov as NCT02029833 (https://www.clinicaltrials.gov/ct2/show/NCT02029833?cond=NCT02029833&rank=1).

Diets Enriched with Conventional or High-Oleic Acid Canola Oils Lower Atherogenic Lipids and Lipoproteins Compared to a Diet with a Western Fatty Acid Profile in Adults with Central Adiposity.

BACKGROUND: Novel oils high in monounsaturated fatty acids (MUFAs) and low in saturated fatty acids (SFAs) are an alternative to partially hydrogenated oils high in trans-unsaturated fatty acids. There is widespread use of high-MUFA oils across the food industry; however, limited knowledge of their cardiovascular impact exists. OBJECTIVES: We investigated the effects of diets containing canola oil, high-oleic acid canola oil (HOCO), and a control oil blend (diet formulated to emulate a Western fat profile) on lipids, lipoproteins, and apolipoproteins (apos), as secondary outcomes of the trial. METHODS: In a multi-center, double-blind, randomized, 3-period crossover, controlled feeding trial, men (n = 44) and women (n = 75) with a mean age of 44 y, mean body mass index (BMI; in kg/m2) of 31.7, and an increased waist circumference plus ≥1 metabolic syndrome criteria consumed prepared, weight-maintenance diets containing canola oil [17.5% MUFAs, 9.2% polyunsaturated fatty acids (PUFAs), 6.6% SFAs], HOCO (19.1% MUFAs, 7.0% PUFAs, 6.4% SFAs), or control oil (10.5% MUFAs, 10.0% PUFAs, 12.3% SFAs) for 6 wk with ≥4-wk washouts. Fasting serum lipids were assessed at baseline and 6 wk. Diet effects were examined using a repeated measures mixed model. RESULTS: Compared with the control, canola and HOCO diets resulted in lower endpoint total cholesterol (TC; -4.2% and -3.4%; P < 0.0001), LDL cholesterol (-6.6% and -5.6%; P < 0.0001), apoB (-3.7% and -3.4%; P = 0.002), and non-HDL cholesterol (-4.5% and -4.0%; P = 0.001), with no differences between canola diets. The TC:HDL cholesterol and apoB:apoA1 ratios were lower after the HOCO diet than after the control diet (-3.7% and -3.4%, respectively). There were no diet effects on triglyceride, HDL cholesterol, or apoA1 concentrations. CONCLUSIONS: HOCO, with increased MUFAs at the expense of decreased PUFAs, elicited beneficial effects on lipids and lipoproteins comparable to conventional canola oil and consistent with reduced cardiovascular disease risk in adults with central adiposity. This trial was registered at www.clinicaltrials.gov as NCT02029833.

Impact of daily incremental change in environmental temperature on beta cell function and the risk of gestational diabetes in pregnant women.

AIMS/HYPOTHESIS: The prevalence of gestational diabetes (GDM) is higher in summer months, possibly reflecting an association between ambient temperature and blood glucose levels. However, the specific exposure and mechanism by which temperature may affect glucose metabolism in pregnancy remains unclear. We systematically evaluated the relationships of environmental temperature and changes therein over varying durations of exposure time with beta cell function, insulin sensitivity and glucose tolerance in women undergoing antepartum screening for GDM. METHODS: At a mean gestation of 29 weeks, 1464 women in Toronto (ON, Canada) underwent an OGTT, from which 318 were diagnosed with GDM. Blood glucose, beta cell function and insulin sensitivity were evaluated in relation to 18 temperature variables: mean temperature and change in temperature on the day of the OGTT and over the preceding 7, 14, 21, 28, 35, 42, 49 and 56 days, respectively. RESULTS: Temperature changes in the preceding 14, 21, 28, 35, 42, 49 and 56 days (rather than mean temperatures) emerged as independent predictors of blood glucose. These relationships were evident in months where mean daily temperature was rising (February - July), but not in those where it was falling (August - January). Indeed, in February - July, the temperature changes in the preceding 21, 28 and 35 days emerged as predictors of both poorer beta cell function and higher blood glucose. Moreover, in February - July, the changes in temperature in the preceding 21 days (OR 1.16, 95% CI 1.01, 1.33) and 28 days (OR 1.20, 95% CI 1.03, 1.39) were independent predictors of GDM, while mean temperatures were not. CONCLUSIONS/INTERPRETATION: In pregnant women, rising environmental temperature in the 3-4 weeks prior to glucose tolerance testing may be associated with beta cell dysfunction and an increased risk of GDM.

Circulating B-type natriuretic peptide in women with and without recent gestational diabetes: The impact of current glucose intolerance.

CONTEXT: Circulating B-type natriuretic peptide, as measured by the N-terminal fragment of its prohormone (NT-proBNP), is inversely associated with incident type 2 diabetes (T2DM) but positively related to future cardiovascular disease (CVD). Recognizing that gestational diabetes (GDM) identifies women at future risk for both T2DM and CVD, we sought to determine whether gestational glucose tolerance relates to NT-proBNP in the years after delivery. DESIGN/PATIENTS/MEASUREMENTS: Three hundred and forty women underwent a glucose challenge test (GCT) and an oral glucose tolerance test (OGTT) in pregnancy, yielding 4 gestational glucose tolerance groups: GDM (n = 105); gestational impaired glucose tolerance (n = 59); abnormal GCT with a normal OGTT (n = 98); and normal GCT with normal OGTT (n = 75). At 3-year postpartum, they underwent cardiometabolic characterization (including measurement of estimated glomerular filtration rate (eGFR), adiponectin and NT-proBNP) and repeated the OGTT, revealing 69 women with glucose intolerance (prediabetes/diabetes). RESULTS: At 3-year postpartum, serum NT-proBNP did not differ between the 4 original gestational glucose tolerance groups (P = .44), but instead progressively decreased across current glucose tolerance strata, from normal to prediabetes to diabetes (P = .006). Indeed, on logistic regression analysis, NT-proBNP emerged as a negative predictor of prediabetes/diabetes (OR = 0.903, 95% CI 0.825-0.988, P = .026). On multiple linear regression analyses of NT-proBNP, the significant association with current glucose intolerance was ultimately attenuated in a fully adjusted model, revealing two independent determinants of NT-proBNP: eGFR (t = -2.71, P = .007) and adiponectin (t = 2.44, P = .015). CONCLUSION: Serum NT-proBNP relates to current glucose intolerance, rather than preceding gestational dysglycaemia. Thus, the diabetic (rather than vascular) risk implications of NT-proBNP predominate in young women.

Rising plasminogen activator inhibitor-1 and hypoadiponectinemia characterize the cardiometabolic biomarker profile of women with recent gestational diabetes.

BACKGROUND: Gestational diabetes (GDM) and milder gestational impaired glucose tolerance (GIGT) identify women at risk of developing type 2 diabetes and cardiovascular disease later in life. Accordingly, the postpartum years after gestational dysglycemia can provide insight into early events in the natural history of these disorders. We thus sought to prospectively evaluate the relationship between gestational glucose tolerance and emerging cardiometabolic biomarkers [adiponectin, chemerin, retinol-binding protein-4 (RBP-4), C-reactive protein (CRP), plasminogen activator inhibitor-1 (PAI-1)] at both 1- and 3-years postpartum in a cohort reflecting the full spectrum of gestational dysglycemia (from normal to GIGT to GDM). METHODS: Three-hundred-and-thirty-nine women completed a glucose challenge test (GCT) and oral glucose tolerance test (OGTT) in pregnancy, which identified 4 gestational glucose tolerance groups: GDM (n = 105); GIGT (n = 59); abnormal GCT with normal OGTT (n = 99); and normal GCT with normal OGTT (n = 76). At 1- and 3-years postpartum, the women underwent repeat OGTT with measurement of biomarkers (adiponectin/chemerin/RBP-4/CRP/PAI-1). RESULTS: Serum adiponectin was lower in women with GDM and GIGT at both 1-year and 3-years (both P ≤ 0.002), whereas chemerin, RBP-4, CRP and PAI-1 showed no differences across the 4 groups. Importantly, the change in PAI-1 between 1- and 3-years progressively increased from the normal GCT group to the abnormal GCT group to GIGT to GDM (P = 0.03). Indeed, both GDM (t = 2.98, P = 0.003) and GIGT (t = 2.14, P = 0.03) independently predicted an increase in PAI-1 from 1- to 3-years postpartum. CONCLUSIONS: Hypoadiponectinemia and rising PAI-1 over time are early features of the cardiometabolic biomarker profile of women with recent gestational dysglycemia.

Diets Low in Saturated Fat with Different Unsaturated Fatty Acid Profiles Similarly Increase Serum-Mediated Cholesterol Efflux from THP-1 Macrophages in a Population with or at Risk for Metabolic Syndrome: The Canola Oil Multicenter Intervention Trial.

Background: Cholesterol efflux plays an important role in preventing atherosclerosis progression. Vegetable oils with varying unsaturated fatty acid profiles favorably affect multiple cardiovascular disease risk factors; however, their effects on cholesterol efflux remain unclear. Objective: The objectives of this study were to examine the effects of diets low in saturated fatty acids (SFAs) with varying unsaturated fatty acid profiles on serum-mediated cholesterol efflux and its association with the plasma lipophilic index and central obesity. Methods: The present study is a randomized, crossover, controlled-feeding study. Participants [men: n = 50; women: n = 51; mean ± SE age: 49.5 ± 1.2 y; body mass index (in kg/m2): 29.4 ± 0.4] at risk for or with metabolic syndrome (MetS) were randomly assigned to 5 isocaloric diets containing the treatment oils: canola oil, high oleic acid-canola oil, DHA-enriched high oleic acid-canola oil, corn oil and safflower oil blend, and flax oil and safflower oil blend. These treatment oils were incorporated into smoothies that participants consumed 2 times/d. For a 3000-kcal diet, 60 g of treatment oil was required to provide 18% of total energy per day. Each diet period was 4 wk followed by a 2- to 4-wk washout period. We quantified cholesterol efflux capacity with a validated ex vivo high-throughput cholesterol efflux assay. Statistical analyses were performed with the use of the SAS mixed-model procedure. Results: The 5 diets increased serum-mediated cholesterol efflux capacity from THP-1 macrophages similarly by 39%, 34%, 55%, 49% and 51%, respectively, compared with baseline (P < 0.05 for all). Waist circumference and abdominal adiposity were negatively correlated with serum-mediated cholesterol efflux capacity (r = -0.25, P = 0.01, r = -0.33, P = 0.02, respectively). Conclusion: Diets low in SFAs with different monounsaturated fatty acid and polyunsaturated fatty acid profiles improved serum-mediated cholesterol efflux capacity in individuals with or at risk for MetS. This mechanism may account, in part, for the cardiovascular disease benefits of diets low in SFAs and high in unsaturated fatty acids. Importantly, central obesity is inversely associated with cholesterol efflux capacity. This trial was registered at www.clinicaltrials.gov as NCT01351012.

Cardiovascular magnetic resonance left ventricular strain in end-stage renal disease patients after kidney transplantation.

BACKGROUND: Cardiovascular disease is a significant cause of morbidity and mortality in patients with end-stage renal disease (ESRD) and kidney transplant (KT) patients. Compared with left ventricular (LV) ejection fraction (LVEF), LV strain has emerged as an important marker of LV function as it is less load dependent. We sought to evaluate changes in LV strain using cardiovascular magnetic resonance imaging (CMR) in ESRD patients who received KT, to determine whether KT may improve LV function. METHODS: We conducted a prospective multi-centre longitudinal study of 79 ESRD patients (40 on dialysis, 39 underwent KT). CMR was performed at baseline and at 12 months after KT. RESULTS: Among 79 participants (mean age 55 years; 30% women), KT patients had significant improvement in global circumferential strain (GCS) (p = 0.007) and global radial strain (GRS) (p = 0.003), but a decline in global longitudinal strain (GLS) over 12 months (p = 0.026), while no significant change in any LV strain was observed in the ongoing dialysis group. For KT patients, the improvement in LV strain paralleled improvement in LVEF (57.4 ± 6.4% at baseline, 60.6% ± 6.9% at 12 months; p = 0.001). For entire cohort, over 12 months, change in LVEF was significantly correlated with change in GCS (Spearman's r = - 0.42, p < 0.001), GRS (Spearman's r = 0.64, p < 0.001), and GLS (Spearman's r = - 0.34, p = 0.002). Improvements in GCS and GRS over 12 months were significantly correlated with reductions in LV end-diastolic volume index and LV end-systolic volume index (all p < 0.05), but not with change in blood pressure (all p > 0.10). CONCLUSIONS: Compared with continuation of dialysis, KT was associated with significant improvements in LV strain metrics of GCS and GRS after 12 months, which did not correlate with blood pressure change. This supports the notion that KT has favorable effects on LV function beyond volume and blood pessure control. Larger studies with longer follow-up are needed to confirm these findings.

Potential biomarkers of tissue hypoxia during acute hemodilutional anemia in cardiac surgery: A prospective study to assess tissue hypoxia as a mechanism of organ injury.

PURPOSE: Hemodilutional anemia is associated with acute kidney injury (AKI) and mortality in patients undergoing cardiac surgery by mechanisms that may include tissue hypoxia. Our hypothesis was to assess if changes in the potential hypoxic biomarkers, including methemoglobin and erythropoietin, correlated with a decrease in hemoglobin (Hb) concentration following hemodilution on cardiopulmonary bypass (CPB). METHODS: Arterial blood samples were taken from patients (n = 64) undergoing heart surgery and CPB at baseline, during CPB, following CPB, and in the intensive care unit (ICU). Potential hypoxic biomarkers were measured, including methemoglobin, plasma Hb, and erythropoietin. Data were analyzed by repeated measures one-way analysis of variance on ranks and linear regression. RESULTS: Hemoglobin levels decreased following CPB and methemoglobin increased in the ICU (P < 0.001 for both). No correlation was observed between the change in Hb and methemoglobin (P = 0.23). By contrast, reduced Hb on CPB correlated with increased lactate, reduced pH, and increased erythropoietin levels following CPB (P ≤ 0.004 for all). Increased plasma Hb (P < 0.001) also correlated with plasma erythropoietin levels (P < 0.001). CONCLUSION: These data support the hypothesis that erythropoietin rather than methemoglobin is a potential biomarker of anemia-induced tissue hypoxia. The observed relationships between decreased Hb during CPB and the increase in lactate, reduced pH, and increase in erythropoietin levels suggest that early changes in plasma erythropoietin may be a pragmatic early biomarker of anemia-induced renal hypoxia. Further study is required to determine if anemia-induced increases in erythropoietin may predict AKI in patients undergoing cardiac surgery. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT01883713). Registered 21 June 2013.

Prior lactation reduces future diabetic risk through sustained postweaning effects on insulin sensitivity.

Breastfeeding for ≥12 mo is recommended for optimal infant nutrition but may hold maternal benefits as well. Indeed, lactation has been associated with lower long-term risk of diabetes in the mother, but the mechanism by which it imparts sustained postweaning effects on glucose tolerance remains unclear. In this context, we postulated that lactation could potentially induce postweaning beneficial effects on glucose tolerance by modifying the natural history of insulin sensitivity and/or pancreatic ß-cell function over time. Thus, in this study, we evaluated the relationships between duration of lactation [≤3 mo (n = 70), 3-12 mo (n = 140), and ≥12 mo (n = 120)] and trajectories of insulin sensitivity/resistance, ß-cell function, and glycemia over the first 3 yr postpartum in a cohort of 330 women comprising the full spectrum of glucose tolerance in pregnancy, who underwent serial metabolic characterization, including oral glucose tolerance tests, at 3 mo, 1 yr, and 3 yr postpartum. The prevalence of dysglycemia (pre-diabetes/diabetes) at 3 yr postpartum was lower in women who breastfed for ≥12 mo (12.5%) than in those who breastfed for ≤3 mo (21.4%) or for 3-12 mo (25.7%)(overall P = 0.028). On logistic regression analysis, lactation for ≥12 mo independently predicted a lower likelihood of prediabetes/diabetes at 3 yr postpartum (OR = 0.37, 95% CI 0.18-0.78, P = 0.009). Notably, lactation for ≥12 mo predicted lesser worsening of insulin sensitivity/resistance (P < 0.0001), fasting glucose (P < 0.0001), and 2-h glucose (P = 0.011) over 3 yr compared with lactation ≤3 mo but no differences in ß-cell function (P ≥ 0.37). It has thus emerged that adherence to current breastfeeding recommendations reduces future diabetic risk through sustained postweaning effects on insulin sensitivity/resistance but not ß-cell function.

Chronic liraglutide therapy induces an enhanced endogenous glucagon-like peptide-1 secretory response in early type 2 diabetes.

Sustained exogenous stimulation of a hormone-specific receptor can affect endogenous hormonal regulation. In this context, little is known about the impact of chronic treatment with glucagon-like peptide-1 (GLP-1) agonists on the endogenous GLP-1 response. We therefore evaluated the impact of chronic liraglutide therapy on endogenous GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) response to an oral glucose challenge. A total of 51 people with type 2 diabetes of 2.6 ± 1.9 years' duration were randomized to daily subcutaneous liraglutide or placebo injection and followed for 48 weeks, with an oral glucose tolerance test (OGTT) every 12 weeks. GLP-1 and GIP responses were assessed according to their respective area under the curve (AUC) from measurements taken at 0, 30, 60, 90 and 120 minutes during each OGTT. There were no differences in AUCGIP between the groups. By contrast, although fasting GLP-1 was unaffected, the liraglutide arm had ~2-fold higher AUCGLP-1 at 12 weeks ( P < .001), 24 weeks ( P < .001), 36 weeks ( P = .03) and 48 weeks ( P = .03), as compared with placebo. Thus, chronic liraglutide therapy induces a previously unrecognized, robust and durable enhancement of the endogenous GLP-1 response, highlighting the need for further study of the long-term effects of incretin mimetics on L-cell physiology.

Preeclampsia and Preterm Birth Associated With Visceral Adiposity in Early Pregnancy.

OBJECTIVE: To determine if an increasing amount of visceral adipose tissue, measured by ultrasound in early pregnancy, is associated with a higher risk of preeclampsia and preterm birth (PTB). METHODS: We completed a prospective cohort study of 463 pregnant women. Maternal visceral adiposity tissue (VAT) depth was measured by ultrasound at 11 to 14 weeks' gestation. Relative risks (RR) were adjusted for age, parity, chronic hypertension, pre-pregnancy BMI, and use of acetylsalicylic acid. RESULTS: The rate of preeclampsia was much higher at quintile (Q) 5 of VAT depth (9.8%) than at Q1 to Q4 (1.6%) but not significantly so in the adjusted model (RR 3.39, 95% CI 0.86 to 13.39). The adjusted RR of PTB was significantly elevated at Q5 VAT depth (6.53, 95% CI 1.47 to 6.53), as was preeclampsia with PTB (16.91, 95% CI 1.24 to 231.07). CONCLUSION: Higher amounts of VAT in pregnancy may play a direct role in the pathogenesis of preeclampsia, including early onset preeclampsia necessitating preterm delivery.

Non-Alcoholic Fatty Liver Disease in Early Pregnancy Predicts Dysglycemia in Mid-Pregnancy: Prospective Study.

OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is mediated by insulin resistance, as is gestational diabetes mellitus (GDM). NAFLD has not been studied in relation to GDM. The objective of this study was to assess the association between first-trimester sonographic findings of NAFLD, and both dysglycemia and GDM in mid-pregnancy. METHODS: We followed a prospective cohort design at a large obstetrics clinic in Toronto, Ontario with 476 women enrolled in early pregnancy. NAFLD was assessed by ultrasound at 11-14 weeks gestation, and standardized images were independently scored by two ultrasonographers for the presence of hepatorenal contrast (one finding) and/or blurring of the intrahepatic vessels (one finding), relative to neither being present. Logistic regression analysis was used to generate odds ratios (ORs) and 95% confidence interval (CI) for the relation between 0, 1, or 2 sonographic findings of NAFLD and the composite outcome of impaired fasting glucose, impaired glucose tolerance, or GDM at 24-28 weeks gestation, determined by a fasting 75-g oral glucose tolerance test. ORs were adjusted (aOR) for maternal age, ethnicity, first-degree relative with type 2 DM, body mass index (BMI) at 11-14 weeks gestation, and change in BMI from 11-14 to 24-28 weeks gestation. RESULTS: Fifty out of 476 women (10.5%) developed the composite outcome. The presence of 1 (aOR 2.0, 95% CI: 1.0-4.1) or 2 (aOR 2.9, 95% CI: 1.0-18.4) sonographic features of NAFLD predicted the composite outcome. Limiting the analysis to ≥1 feature vs. none, the aOR was 2.2 (95% CI: 1.1-4.3). CONCLUSIONS: Sonographic assessment of NAFLD is a semiquantitative measure, with limited ability to detect small amounts of hepatic steatosis, or to distinguish various stages of NAFLD. First-trimester sonographic evidence of NAFLD predicts dysglycemia in mid-pregnancy.

The persistence of maternal vitamin D deficiency and insufficiency during pregnancy and lactation irrespective of season and supplementation.

BACKGROUND: Pregnancy and lactation comprise a critical window spanning all seasons during which maternal vitamin D status potentially may influence the long-term health of the newborn. Women typically receive calcium/vitamin D supplementation through antenatal vitamins, but there has been limited serial evaluation of maternal vitamin D status across this critical window. DESIGN/PATIENTS/MEASUREMENTS: In this prospective observational cohort study, 467 women in Toronto, Canada, underwent measurement of serum 25-hydroxy vitamin D (25-OH-D) at mean 29·7 ± 2·9 weeks' gestation, 3 months postpartum and 12 months postpartum, enabling serial assessment across 3 seasons. At each assessment, vitamin D status was classified as deficiency (25-OH-D<50 nmol/l), insufficiency (25-OH-D≥50 nmol/l and <75 nmol/l) or sufficiency (25-OH-D≥75 nmol/l). RESULTS: The prevalence rates of vitamin D deficiency and insufficiency were 31·5% and 35·1% in pregnancy, 33·4% and 35·3% at 3 months, and 35·6% and 33·8% at 12 months postpartum, respectively. These high rates remained stable over time (P = 0·49) despite declining usage of antenatal calcium/vitamin D supplementation from pregnancy to 3 months to 12 months postpartum (P < 0·001). Indeed, on mixed model analyses, vitamin D deficiency and insufficiency in pregnancy were independently associated with decrements in average 25-OH-D over time of 49·6 nmol/l and 26·4 nmol/l, respectively (both P < 0·001). In contrast, season of baseline assessment and use of calcium/vitamin D supplements were independently associated with changes in 25-OH-D in the range of 3-5 nmol/l (both P < 0·008). CONCLUSIONS: The persistence of vitamin D deficiency/insufficiency during pregnancy and lactation, irrespective of season and supplementation, supports the emerging concept that current vitamin D supplementation in antenatal care is likely inadequate.