Epigenetics in diabetic nephropathy, immunity and metabolism

When it comes to the epigenome, there is a fine line between clarity and confusion-walk that line and you will discover another fascinating level of transcription control. With the genetic code representing the cornerstone of rules for information that is encoded to proteins somewhere above the genome level there is a set of rules by which chemical information is also read. These epigenetic modifications show a different side of the genetic code that is diverse and regulated, hence modifying genetic transcription transiently, ranging from short- to long-term alterations. While this complexity brings exquisite control it also poses a formidable challenge to efforts to decode mechanisms underlying complex disease. Recent technological and computational advances have improved unbiased acquisition of epigenomic patterns to improve our understanding of the complex chromatin landscape. Key to resolving distinct chromatin signatures of diabetic complications is the identification of the true physiological targets of regulatory proteins, such as reader proteins that recognise, writer proteins that deposit and eraser proteins that remove specific chemical moieties. But how might a diverse group of proteins regulate the diabetic landscape from an epigenomic perspective? Drawing from an ever-expanding compendium of experimental and clinical studies, this review details the current state-of-play and provides a perspective of chromatin-dependent mechanisms implicated in diabetic complications, with a special focus on diabetic nephropathy. We hypothesise a codified signature of the diabetic epigenome and provide examples of prime candidates for chemical modification. As for the pharmacological control of epigenetic marks, we explore future strategies to expedite and refine the search for clinically relevant discoveries. We also consider the challenges associated with therapeutic strategies targeting epigenetic pathways.

Associations of maternal quitting, reducing, and continuing smoking during pregnancy with longitudinal fetal growth: Findings from Mendelian randomization and parental negative control studies

BACKGROUND

Maternal smoking during pregnancy is an established risk factor for low infant birth weight, but evidence on critical exposure windows and timing of fetal growth restriction is limited. Here we investigate the associations of maternal quitting, reducing, and continuing smoking during pregnancy with longitudinal fetal growth by triangulating evidence from 3 analytical approaches to strengthen causal inference.

METHODS AND FINDINGS

We analysed data from 8,621 European liveborn singletons in 2 population-based pregnancy cohorts (the Generation R Study, the Netherlands 2002-2006 [n = 4,682]) and the Born in Bradford study, United Kingdom 2007-2010 [n = 3,939]) with fetal ultrasound and birth anthropometric measures, parental smoking during pregnancy, and maternal genetic data. Associations with trajectories of estimated fetal weight (EFW) and individual fetal parameters (head circumference, femur length [FL], and abdominal circumference [AC]) from 12-16 to 40 weeks' gestation were analysed using multilevel fractional polynomial models. We compared results from (1) confounder-adjusted multivariable analyses, (2) a Mendelian randomization (MR) analysis using maternal rs1051730 genotype as an instrument for smoking quantity and ease of quitting, and (3) a negative control analysis comparing maternal and mother's partner's smoking associations. In multivariable analyses, women who continued smoking during pregnancy had a smaller fetal size than non-smokers from early gestation (16-20 weeks) through to birth (p-value for each parameter < 0.001). Fetal size reductions in continuing smokers followed a dose-dependent pattern (compared to non-smokers, difference in mean EFW [95% CI] at 40 weeks' gestation was -144 g [-182 to -106], -215 g [-248 to -182], and -290 g [-334 to -247] for light, moderate, and heavy smoking, respectively). Overall, fetal size reductions were most pronounced for FL. The fetal growth trajectory in women who quit smoking in early pregnancy was similar to that of non-smokers, except for a shorter FL and greater AC around 36-40 weeks' gestation. In MR analyses, each genetically determined 1-cigarette-per-day increase was associated with a smaller EFW from 20 weeks' gestation to birth in smokers (p = 0.01, difference in mean EFW at 40 weeks = -45 g [95% CI -81 to -10]) and a greater EFW from 32 weeks' gestation onwards in non-smokers (p = 0.03, difference in mean EFW at 40 weeks = 26 g [95% CI 5 to 47]). There was no evidence that partner smoking was associated with fetal growth. Study limitations include measurement error due to maternal self-report of smoking and the modest sample size for MR analyses resulting in unconfounded estimates being less precise. The apparent positive association of the genetic instrument with fetal growth in non-smokers suggests that genetic pleiotropy may have masked a stronger association in smokers.

CONCLUSIONS

A consistent linear dose-dependent association of maternal smoking with fetal growth was observed from the early second trimester onwards, while no major growth deficit was found in women who quit smoking early in pregnancy except for a shorter FL during late gestation. These findings reinforce the importance of smoking cessation advice in preconception and antenatal care and show that smoking reduction can lower the risk of impaired fetal growth in women who struggle to quit.

Socio-economic status and HbA1c in type 2 diabetes: A systematic review and meta-analysis

Up until now, differences in HbA_1c levels by socio-economic status (SES) have been identified, but not yet quantified in people with type 2 diabetes. The aim of this study was therefore to assess the difference in HbA_1c levels between people with type 2 diabetes of different SES in a systematic review and meta-analysis. A systematic literature search was conducted in MEDLINE, Embase, Ebsco, and the Cochrane Library until January 14, 2018. Included studies described adults with type 2 diabetes in whom the association between SES and HbA_1c levels was studied. Studies were rated for methodological quality and data were synthesized quantitatively (meta-analysis) and qualitatively (levels of evidence), stratified for type of SES variable, i.e., education, income, deprivation, and employment. Fifty-one studies were included: 15 high, 27 moderate, and 9 of low methodological quality. Strong evidence was provided that people of low SES have higher HbA_1c levels than people of high SES, for deprivation, education, and employment status. The pooled mean difference in HbA_1c levels between people of low and high SES was 0.26% (95% CI, 0.09-0.43) or 3.12 mmol/mol (95% CI, 1.21-5.04) for education and 0.20% (95% CI, -0.05 to 0.46) or 2.36 mmol/mol (95%CI, -0.61 to 5.33) for income. In conclusion, our systematic review and meta-analysis showed that there was an inverse association between SES and HbA_1c levels in people with type 2 diabetes. Future research should focus on finding SES-sensitive strategies to reduce HbA_1c levels in people with type 2 diabetes.

Muscle-specific inflammation induced by MCP-1 overexpression does not affect whole-body insulin sensitivity in mice

AIMS/HYPOTHESIS

Obesity is associated with a state of chronic low-grade inflammation that is believed to contribute to the development of skeletal muscle insulin resistance. However, the extent to which local and systemic elevation of cytokines, such as monocyte chemoattractant protein 1 (MCP-1), interferes with the action of insulin and promotes insulin resistance and glucose intolerance in muscle remains unclear. Here, we aim to investigate the effect of muscle-specific overexpression of MCP-1 on insulin sensitivity and glucose tolerance in lean and obese mice.

METHODS

We used Mck-Mcp-1 transgenic (Tg) mice characterised by muscle-specific overexpression of Mcp-1 (also known as Ccl2) and elevated plasma MCP-1 levels. Mice were fed either chow or high-fat diet for 10 weeks. Numerous metabolic variables were measured, including glucose and insulin tolerance tests, muscle insulin signalling and plasma NEFA, triacylglycerol, cholesterol, glucose and insulin.

RESULTS

Despite clearly promoting skeletal muscle inflammation, muscle-specific overexpression of Mcp-1 did not influence glucose tolerance or insulin sensitivity in either lean chow-fed or diet-induced obese mice. In addition, plasma NEFA, triacylglycerol, cholesterol, glucose and insulin were not affected by MCP-1 overexpression. Finally, in vivo insulin-induced Akt phosphorylation in skeletal muscle did not differ between Mcp-1-Tg and wild-type mice.

CONCLUSIONS/INTERPRETATION

We show that increased MCP-1 production in skeletal muscle and concomitant elevated MCP-1 levels in plasma promote inflammation in skeletal muscle but do not influence insulin signalling and have no effect on insulin resistance and glucose tolerance in lean and obese mice. Overall, our data argue against MCP-1 promoting insulin resistance in skeletal muscle and raise questions about the impact of inflammation on insulin sensitivity in muscle.

How to identify clinically significant diabetes distress using the Problem Areas in Diabetes (PAID) scale in adults with diabetes treated in primary or secondary care? Evidence for new cut points based on latent class analyses

INTRODUCTION

The Problem Areas of Diabetes (PAID) questionnaire is a frequently used measure to assess diabetes-distress. The aim of this study was to identify clinically meaningful levels of diabetes-distress, using latent class analyses (LCA), and to determine which groups were at increased risk of elevated diabetes-distress in terms of sex, age, type of diabetes and glycaemic control.

METHODS

Data were derived from four studies (total N=2966, 49% female, age range 18-95 years, 43% type 1 diabetes, diabetes duration range 0-79 years). LCAs were performed to examine possible latent groups in the distribution of answers on the individual PAID items. Demographic and diabetes-related characteristics were added to the model to estimate their effects on latent class membership and receiver operating curves curves to determine cut-offs.

RESULTS

Three levels of diabetes distress were distinguished with defined cut-off scores and labelled as: low, moderate and high diabetes distress. Levels of distress did not associate with distinct clusters of items. Older people were more likely to be part of the low distress class; women and people with high HbA_1c were more likely to be part of the high distress class. Sensitivity and specificity of the commonly used cut-off of 40 for high distress are 0.95 and 0.97, respectively. To distinguish the moderate distress group, cut-off scores of 17 and 39 are optimal with a sensitivity of 0.93 and a specificity of 0.94.

CONCLUSION

Three levels of diabetes-distress can be distinguished: low, moderate and high diabetes distress. Younger people, women and people with poor glycaemic control are at an increased risk for high levels of distress. A cut-off of 40 is satisfactory to detect people with high levels of diabetes-distress; a score of 0-16 indicates low diabetes distress and a score of 17-39 moderate diabetes distress.

A three-dimensional atlas of child's cardiac anatomy and the unique morphological alterations associated with obesity

AIMS

Statistical shape models (SSMs) of cardiac anatomy provide a new approach for analysis of cardiac anatomy. In adults, specific cardiac morphologies associate with cardiovascular risk factors and early disease stages. However, the relationships between morphology and risk factors in children remain unknown. We propose an SSM of the paediatric left ventricle to describe its morphological variability, examine its relationship with biometric parameters and identify adverse anatomical remodelling associated with obesity.

METHODS AND RESULTS

This cohort includes 2631 children (age 10.2 ± 0.6 years), mostly Western European (68.3%) with a balanced sex distribution (51.3% girls) from Generation R study. Cardiac magnetic resonance short-axis cine scans were segmented. Three-dimensional left ventricular (LV) meshes are automatically fitted to the segmentations to reconstruct the anatomies. We analyse the relationships between the LV anatomical features and participants' body surface area (BSA), age, and sex, and search for features uniquely related to obesity based on body mass index (BMI). In the SSM, 19 modes described over 90% of the population's LV shape variability. Main modes of variation were related to cardiac size, sphericity, and apical tilting. BSA, age, and sex were mostly correlated with modes describing LV size and sphericity. The modes correlated uniquely with BMI suggested that obese children present with septo-lateral tilting (R2 = 4.0%), compression in the antero-posterior direction (R2 = 3.3%), and decreased eccentricity (R2 = 2.0%).

CONCLUSIONS

We describe the variability of the paediatric heart morphology and identify anatomical features related to childhood obesity that could aid in risk stratification. Web service is released to provide access to the new shape parameters.

Sodium glucose cotransporter (SGLT)-2 inhibitors: Do we need them for glucose-lowering, for cardiorenal protection or both?

Sodium glucose cotransporter (SGLT)-2 inhibitors are the newest addition to our treatment armamentarium for the management of hyperglycemia in type 2 diabetes. Glucose-lowering per se reduces the risk of microvascular complications, but not the risk of cardiovascular disease, including heart failure and cardiovascular mortality. Also, even when embedded in optimal cardiovascular prevention, a large residual risk remains with respect to progression of diabetic kidney disease. SGLT-2 inhibitors lower blood glucose levels by inducing glucosuria. Through various proposed mechanisms, among which diuretic and natriuretic effects, SGLT-2 inhibitors decrease heart failure hospitalization, reduce cardiovascular mortality, and mitigate progression of diabetic kidney disease. In this perspective, we will discuss the glucose-lowering and other protective effects of SGLT-2 inhibitors on the cardiorenal axis, both in primary and secondary prevention. By comparing the glycemic and pleiotropic effects of these agents to other glucose-lowering drugs, we will address questions around whether SGLT-2 inhibitors should be considered primarily as glucose-lowering agents, cardiorenal drugs or both.

Maternal Body Mass Index, Early-Pregnancy Metabolite Profile, and Birthweight

CONTEXT

Maternal prepregnancy body mass index (BMI) has a strong influence on gestational metabolism, but detailed metabolic alterations are unknown.

OBJECTIVE

First, to examine the associations of maternal prepregnancy BMI with maternal early-pregnancy metabolite alterations. Second, to identify an early-pregnancy metabolite profile associated with birthweight in women with a higher prepregnancy BMI that improved prediction of birthweight compared to glucose and lipid concentrations.

DESIGN, SETTING, AND PARTICIPANTS

Prepregnancy BMI was obtained in a subgroup of 682 Dutch pregnant women from the Generation R prospective cohort study.

MAIN OUTCOME MEASURES

Maternal nonfasting targeted amino acids, nonesterified fatty acid, phospholipid, and carnitine concentrations measured in blood serum at mean gestational age of 12.8 weeks. Birthweight was obtained from medical records.

RESULTS

A higher prepregnancy BMI was associated with 72 altered amino acids, nonesterified fatty acid, phospholipid and carnitine concentrations, and 6 metabolite ratios reflecting Krebs cycle, inflammatory, oxidative stress, and lipid metabolic processes (P-values < 0.05). Using penalized regression models, a metabolite profile was selected including 15 metabolites and 4 metabolite ratios based on its association with birthweight in addition to prepregnancy BMI. The adjusted R2 of birthweight was 6.1% for prepregnancy BMI alone, 6.2% after addition of glucose and lipid concentrations, and 12.9% after addition of the metabolite profile.

CONCLUSIONS

A higher maternal prepregnancy BMI was associated with altered maternal early-pregnancy amino acids, nonesterified fatty acids, phospholipids, and carnitines. Using these metabolites, we identified a maternal metabolite profile that improved prediction of birthweight in women with a higher prepregnancy BMI compared to glucose and lipid concentrations.

Cold-Induced Thermogenesis Shows a Diurnal Variation That Unfolds Differently in Males and Females

CONTEXT

Cold exposure mobilizes lipids to feed thermogenic processes in organs, including brown adipose tissue (BAT). In rodents, BAT metabolic activity exhibits a diurnal rhythm, which is highest at the start of the wakeful period.

OBJECTIVE

We investigated whether cold-induced thermogenesis displays diurnal variation in humans and differs between the sexes.

METHODS

This randomized crossover study included 24 young and lean male (n = 12) and female (n = 12) participants who underwent 2.5-hour personalized cooling using water-perfused mattresses in the morning (7:45 am) and evening (7:45 pm), with 1 day in between. We measured energy expenditure (EE) and supraclavicular skin temperature in response to cold exposure.

RESULTS

In males, cold-induced EE was higher in the morning than in the evening (+54% ± 10% vs +30% ± 7%; P = 0.05) but did not differ between morning and evening in females (+37% ± 9% vs +30% ± 10%; P = 0.42). Only in males, supraclavicular skin temperature upon cold increased more in morning than evening (+0.2 ± 0.1 °C vs -0.2 ± 0.2 °C; P = 0.05). In males, circulating free fatty acid (FFA) levels were increased after morning cold exposure, but not evening (+90% ± 18% vs +9% ± 8%; P < 0.001). In females, circulating FFA (+94% ± 21% vs +20% ± 5%; P = 0.006), but also triglycerides (+42% ± 5% vs +29% ± 4%, P = 0.01) and cholesterol levels (+17% ± 2% vs 11% ± 2%; P = 0.05) were more increased after cold exposure in morning than in evening.

CONCLUSION

Cold-induced thermogenesis is higher in morning than evening in males; however, lipid metabolism is more modulated in the morning than the evening in females.

Food choices: concordance in Australian children aged 11-12 years and their parents

OBJECTIVES

Snack foods-typically high in salt, sugar, fat and/or energy-are likely important to the obesity epidemic. In the context of a population-based health assessment involving parent-child dyads at child age 11-12 years, we report cross-generational concordance in intake at a controlled snack food observation.

DESIGN

Cross-sectional study (Child Health CheckPoint), nested within the Longitudinal Study of Australian Children.

SETTING

Assessment centres in seven Australian cities, February 2015-March 2016.

PARTICIPANTS

Of all participating CheckPoint families (n=1874), 1299 children (50.3% girls) and 1274 parents (85.9% mothers) with snack data were included. Survey weights and methods were applied to account for the clustered multistage sample design.

OUTCOME MEASURES

Partway through the 3.5-hour assessment, parents and children attended Food Stop separately for a timed 15 min 'snack break'. One of four standardised box size/content combinations was randomly provided to all participants on any given day. Total food mass, energy, nutrients and sodium consumed was measured to the nearest 1 g. Pearson's correlation coefficients and adjusted multivariable linear regression models assessed parent-child concordance in each variable.

RESULTS

Children consumed less grams (151 g [SD 80] vs 165 g [SD 79]) but more energy (1393 kJ [SD 537] vs 1290 kJ [SD 658]) than parents. Parent-child concordance coefficients were small, ranging from 0.07 for sodium intake to 0.17 for carbohydrate intake. Compared with children with parents' energy intake on the 10th centile, children whose parents were on the 90th centile ate on average 227 kJ more. If extrapolated to one similar unsupervised snack on a daily basis, this equates to an additional 83 050 kJ per year, which could have a cumulative impact on additional body fat.

CONCLUSIONS

Although modest at an individual level, this measured parent-child concordance in unsupervised daily snack situations could account for substantial annual population differences in energy, fat and sodium intake for children aged 11-12 years.

TRIAL REGISTRATION NUMBER

ISRCTN12538380.

Arterial wall inflammation assessed by 18F-FDG-PET/CT is higher in individuals with Type 1 diabetes and associated with circulating inflammatory proteins

AIMS

The article investigates whether chronic hyperglycaemia in Type 1 diabetes (T1D) is associated with a proinflammatory immune signature and with arterial wall inflammation, driving the development of atherosclerosis.

METHODS AND RESULTS

Patients with T1D (n = 41), and healthy age-, sex-, and body mass index-matched controls (n = 20) were recruited. Arterial wall inflammation and haematopoietic activity were measured with 2'-deoxy-2'-(18F)-fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography. In addition, flow cytometry of circulating leucocytes was performed as well as targeted proteomics to measure circulating inflammatory markers. 18F-FDG uptake in the wall of the abdominal aorta, carotid arteries, and iliac arteries was higher in T1D compared with that in the healthy controls. Also, 18F-FDG uptake in the bone marrow and spleen was higher in patients with T1D. CCR2 and CD36 expressions on circulating monocytes were higher in patients with T1D, as well as several circulating inflammatory proteins. In addition, several circulating inflammatory markers (osteoprotegerin, transforming growth factor-alpha, CX3CL1, and colony-stimulating factor-1) displayed a positive correlation with FDG uptake. Within T1D, no differences were found between people with a high and low HbA1c.

CONCLUSION

These findings strengthen the concept that chronic hyperglycaemia in T1D induces inflammatory changes that fuel arterial wall inflammation leading to atherosclerosis. The degree of hyperglycaemia appears to play a minor role in driving this inflammatory response in patients with T1D.

Differences in Inflammatory Pathways Between Dutch South Asians vs Dutch Europids With Type 2 Diabetes

CONTEXT

South Asian individuals are more prone to develop type 2 diabetes (T2D) coinciding with earlier complications than Europids. While inflammation plays a central role in the development and progression of T2D, this factor is still underexplored in South Asians.

OBJECTIVE

This work aimed to study whether circulating messenger RNA (mRNA) transcripts of immune genes are different between South Asian compared with Europid patients with T2D.

METHODS

A secondary analysis was conducted of 2 randomized controlled trials of Dutch South Asian (n = 45; age: 55 ± 10 years, body mass index [BMI]: 29 ± 4 kg/m2) and Dutch Europid (n = 44; age: 60 ± 7 years, BMI: 32 ± 4 kg/m2) patients with T2D. Main outcome measures included mRNA transcripts of 182 immune genes (microfluidic quantitative polymerase chain reaction; Fluidigm Inc) in fasted whole-blood, ingenuity pathway analyses (Qiagen).

RESULTS

South Asians, compared to Europids, had higher mRNA levels of B-cell markers (CD19, CD79A, CD79B, CR2, CXCR5, IGHD, MS4A1, PAX5; all fold change > 1.3, false discovery rate [FDR] < 0.008) and interferon (IFN)-signaling genes (CD274, GBP1, GBP2, GBP5, FCGR1A/B/CP, IFI16, IFIT3, IFITM1, IFITM3, TAP1; all FC > 1.2, FDR < 0.05). In South Asians, the IFN signaling pathway was the top canonical pathway (z score 2.6; P < .001) and this was accompanied by higher plasma IFN-γ levels (FC = 1.5, FDR = 0.01). Notably, the ethnic difference in gene expression was larger for women (20/182 [11%]) than men (2/182 [1%]).

CONCLUSION

South Asian patients with T2D show a more activated IFN-signaling pathway compared to Europid patients with T2D, which is more pronounced in women than men. We speculate that a more activated IFN-signaling pathway may contribute to the more rapid progression of T2D in South Asian compared with Europid individuals.

Cystatin C-Based eGFR Changes during Gender-Affirming Hormone Therapy in Transgender Individuals

BACKGROUND

Men with CKD tend to experience a faster eGFR decline than women, potentially because of sex hormones. Limited research exists regarding the effect of gender-affirming hormone therapy (GAHT) on kidney function. Furthermore, monitoring kidney function during GAHT is challenging because serum creatinine is confounded by body composition. To investigate the relationship between sex hormones and kidney function, we studied the changes of serum creatinine and serum cystatin C, a filtration marker less affected by sex, during 1 year of GAHT.

METHODS

As part of the European Network for the Investigation of Gender Incongruence study, we measured serum creatinine and serum cystatin C in 260 transgender women and 285 transgender men before and 12 months after initiating GAHT. Transgender women received estradiol plus cyproterone acetate, while transgender men received testosterone. Cystatin C-based eGFR was calculated using the full-age-spectrum equation.

RESULTS

In transgender women, cystatin C decreased by 0.069 mg/L (95% confidence interval [CI], 0.049 to 0.089), corresponding with a 7 ml/min per 1.73 m 2 increase in eGFR. In transgender men, cystatin C increased by 0.052 mg/L (95% CI, 0.031 to 0.072), corresponding with a 6 ml/min per 1.73 m 2 decrease in eGFR. Creatinine concentrations decreased (-0.065 mg/dl; 95% CI, -0.076 to -0.054) in transgender women and increased (+0.131 mg/dl; 95% CI, 0.119 to 0.142) in transgender men. Changes in creatinine-based eGFR varied substantially depending on the sex used in the equation.

CONCLUSIONS

In this cohort of transgender individuals, cystatin C-based eGFR increased with estradiol and antiandrogen therapy and decreased with testosterone therapy.

Associations of Maternal Early-Pregnancy Glucose Concentrations With Placental Hemodynamics, Blood Pressure, and Gestational Hypertensive Disorders

BACKGROUND

Gestational diabetes mellitus is associated with increased risks of gestational hypertension and preeclampsia. We hypothesized that high maternal glucose concentrations in early pregnancy are associated with adverse placental adaptations and subsequently altered uteroplacental hemodynamics during pregnancy, predisposing to an increased risk of gestational hypertensive disorders.

METHODS

In a population-based prospective cohort study from early pregnancy onwards, among 6,078 pregnant women, maternal early-pregnancy non-fasting glucose concentrations were measured. Mid and late pregnancy uterine and umbilical artery resistance indices were assessed by Doppler ultrasound. Maternal blood pressure was measured in early, mid, and late pregnancy and the occurrence of gestational hypertensive disorders was assessed using hospital registries.

RESULTS

Maternal early-pregnancy glucose concentrations were not associated with mid or late pregnancy placental hemodynamic markers. A 1 mmol/l increase in maternal early-pregnancy glucose concentrations was associated with 0.71 mm Hg (95% confidence interval 0.22-1.22) and 0.48 mm Hg (95% confidence interval 0.10-0.86) higher systolic and diastolic blood pressure in early pregnancy, respectively, but not with blood pressure in later pregnancy. Also, maternal glucose concentrations were not associated with the risks of gestational hypertension or preeclampsia.

CONCLUSIONS

Maternal early-pregnancy non-fasting glucose concentrations within the normal range are associated with blood pressure in early pregnancy, but do not seem to affect placental hemodynamics and the risks of gestational hypertensive disorders.

Maternal First-Trimester Cow-Milk Intake Is Positively Associated with Childhood General and Abdominal Visceral Fat Mass and Lean Mass but Not with Other Cardiometabolic Risk Factors at the Age of 10 Years

BACKGROUND

Higher maternal cow-milk intake during pregnancy is associated with higher fetal growth measures and higher birth weight.

OBJECTIVE

The aim of this study was to assess the associations of maternal milk intake during pregnancy with body fat measures and cardiometabolic risk factors at the age of 10 y.

METHODS

In a population-based cohort of Dutch mothers and their children (n = 2466) followed from early pregnancy onwards, we assessed maternal first-trimester milk intake (milk and milk drinks) by food-frequency questionnaire. Maternal milk intake was categorized into 0-0.9, 1-1.9, 2-2.9, 3-3.9, 4-4.9, and ≥5 glasses/d, with 1 glass equivalent to 150 mL milk. For children at the age of 10 y, we calculated BMI and obtained detailed measures of body and organ fat by DXA and MRI. We also measured blood pressure and lipid, insulin, and glucose concentrations. Data were analyzed using linear and logistic regression models.

RESULTS

Compared with children whose mothers consumed 0-0.9 glass of milk/d during their pregnancy, those whose mothers consumed ≥5 glasses of milk/d had a 0.29 SD (95% CI: 0.10, 0.48) higher BMI, 0.27 SD (95% CI: 0.08, 0.47) higher fat mass, 0.26 SD (95% CI: 0.07, 0.46) higher lean mass, 0.30 SD (95% CI: 0.09, 0.50) higher android-to-gynoid fat mass ratio and 0.38 SD (95% CI: 0.09, 0.67) higher abdominal visceral fat mass. After correction for multiple comparisons, groups of maternal milk intake were not associated with pericardial fat mass index, liver fat fraction, blood pressure, or lipid, insulin, or glucose concentrations (P values >0.0125).

CONCLUSIONS

Our results suggest that maternal first-trimester milk intake is positively associated with childhood general and abdominal visceral fat mass and lean mass, but not with other cardiometabolic risk factors.

Cardiac energy metabolism is decreased in male volunteers with prediabetes and does not normalize during the day

Type 2 diabetes mellitus is characterized by a low cardiac energy status (PCr/ATP ratio), but it is unknown whether this also applies to prediabetes. Since PCr/ATP is correlated with elevated free fatty acids (FFA), a potentially lower PCr/ATP might be secondary to elevated FFA. To investigate this, we determined PCr/ATP and FFA levels in volunteers with prediabetes at two time-points during the day. Eight male volunteers with prediabetes underwent a MRI/MRS scan to determine left ventricular ejection fraction (LVEF) and PCr/ATP ratio at 7 am and at 5 pm. For reference, these results were compared to eight non-insulin resistant overweight or obese volunteers. Myocardial energy status was lower in the volunteers with prediabetes (PCr/ATP 1.03 ± 0.08) compared to non-insulin resistant overweight or obese volunteers (PCr/ATP 1.22 ± 0.04, p < 0.05), but FFA were not significantly different between groups. LVEF was similar in the volunteers with prediabetes compared to healthy overweight and obese volunteers (p = 0.23). Volunteers with prediabetes have a lower myocardial energy status in the morning compared to healthy overweight and obese volunteers, while cardiac function remained normal. In addition, no differences between morning and evening measurements of cardiac energy status and function were found.

PCr/ATP ratios and mitochondrial function in the heart. A comparative study in humans

Cardiac energy status, measured as phosphocreatine (PCr)/adenosine triphosphate (ATP) ratio with 31P-Magnetic Resonance Spectroscopy (31P-MRS) in vivo, is a prognostic factor in heart failure and is lowered in cardiometabolic disease. It has been suggested that, as oxidative phosphorylation is the major contributor to ATP synthesis, PCr/ATP ratio might be a reflection of cardiac mitochondrial function. The objective of the study was to investigate whether PCr/ATP ratios can be used as in vivo marker for cardiac mitochondrial function. We enrolled thirty-eight patients scheduled for open-heart surgery in this study. Cardiac 31P-MRS was performed before surgery. Tissue from the right atrial appendage was obtained during surgery for high-resolution respirometry for the assessment of mitochondrial function. There was no correlation between the PCr/ATP ratio and ADP-stimulated respiration rates (octanoylcarnitine R² < 0.005, p = 0.74; pyruvate R² < 0.025, p = 0.41) nor with maximally uncoupled respiration (octanoylcarnitine R² = 0.005, p = 0.71; pyruvate R² = 0.040, p = 0.26). PCr/ATP ratio did correlate with indexed LV end systolic mass. As no direct correlation between cardiac energy status (PCr/ATP) and mitochondrial function in the heart was found, the study suggests that mitochondrial function might not the only determinant of cardiac energy status. Interpretation should be done in the right context in cardiac metabolic studies.

The Infrared Thermography Toolbox: An Open-access Semi-automated Segmentation Tool for Extracting Skin Temperatures in the Thoracic Region including Supraclavicular Brown Adipose Tissue

Infrared thermography (IRT) is widely used to assess skin temperature in response to physiological changes. Yet, it remains challenging to standardize skin temperature measurements over repeated datasets. We developed an open-access semi-automated segmentation tool (the IRT-toolbox) for measuring skin temperatures in the thoracic area to estimate supraclavicular brown adipose tissue (scBAT) activity, and compared it to manual segmentations. The IRT-toolbox, designed in Python, consisted of image pre-alignment and non-rigid image registration. The toolbox was tested using datasets of 10 individuals (BMI = 22.1 ± 2.1 kg/m², age = 22.0 ± 3.7 years) who underwent two cooling procedures, yielding four images per individual. Regions of interest (ROIs) were delineated by two raters in the scBAT and deltoid areas on baseline images. The toolbox enabled direct transfer of baseline ROIs to the registered follow-up images. For comparison, both raters also manually drew ROIs in all follow-up images. Spatial ROI overlap between methods and raters was determined using the Dice coefficient. Mean bias and 95% limits of agreement in mean skin temperature between methods and raters were assessed using Bland-Altman analyses. ROI delineation time was four times faster with the IRT-toolbox (01:04 min) than with manual delineations (04:12 min). In both anatomical areas, there was a large variability in ROI placement between methods. Yet, relatively small skin temperature differences were found between methods (scBAT: 0.10 °C, 95%LoA[-0.13 to 0.33 °C] and deltoid: 0.05 °C, 95%LoA[-0.46 to 0.55 °C]). The variability in skin temperature between raters was comparable between methods. The IRT-toolbox enables faster ROI delineations, while maintaining inter-user reliability compared to manual delineations. (Trial registration number (ClinicalTrials.gov): NCT04406922, [May 29, 2020]).

Nuclear receptor Nur77 and Yin-Yang 1 synergistically increase mitochondrial abundance and activity in macrophages

Mitochondrial biogenesis requires precise regulation of both mitochondrial-encoded and nuclear-encoded genes. Nuclear receptor Nur77 is known to regulate mitochondrial metabolism in macrophages and skeletal muscle. Here, we compared genome-wide Nur77 binding site and target gene expression in these two cell types, which revealed conserved regulation of mitochondrial genes and enrichment of motifs for the transcription factor Yin-Yang 1 (YY1). We show that Nur77 and YY1 interact, that YY1 increases Nur77 activity, and that their binding sites are co-enriched at mitochondrial ribosomal protein gene loci in macrophages. Nur77 and YY1 co-expression synergistically increases Mrpl1 expression as well as mitochondrial abundance and activity in macrophages but not skeletal muscle. As such, we identify a macrophage-specific Nur77-YY1 interaction that enhances mitochondrial metabolism.

Prevalence and predictive features of metabolic dysfunction-associated steatotic liver disease in type 1 diabetes

AIMS/HYPOTHESIS

The prevalence and severity of metabolic dysfunction-associated steatotic liver disease (MASLD) in type 1 diabetes remain unclear. Therefore, we investigated the prevalence and severity of MASLD in type 1 diabetes and assessed which clinical features are most important in predicting MASLD severity.

METHODS

A total of 453 individuals with type 1 diabetes (41.6 ± 15.0 years, 64% female, body mass index [BMI] 25.4 ± 4.2 kg/m2, and HbA1c 55.6 ± 12 mmol/mol) underwent vibration-controlled transient elastography (VCTE), with a controlled attenuation parameter (CAP) score for steatosis (≥280.0 dB/m) and a liver stiffness measurement (LMS) for fibrosis (≥8.0 kPa). A machine learning Extra-Trees classification model was performed to assess the predictive power of the clinical features associated with type 1 diabetes with respect to steatosis and fibrosis.

RESULTS

The prevalence of hepatic steatosis and fibrosis was 9.5% (95% CI, 6.8-12.2) and 3.5% (95% CI, 1.8-5.2). Higher LMS was associated with a longer duration of type 1 diabetes (median 30.5 [IQR 18.0-39.3] years vs 15.0 [IQR 6.0-27.0] years), and individuals were older, had a higher BMI (mean 27.8 ± 5.2 vs 25.3 ± 4.1 kg/m2), and a higher CAP score (mean 211.4 ± 51.7 dB/m vs 241.4 ± 75.6 dB/m). The most important predictive features of fibrosis were duration of type 1 diabetes, age, and systolic blood pressure, with a mean ± SD area under the curve of 0.73 ± 0.03.

CONCLUSION

Individuals with type 1 diabetes and high blood pressure, older age, higher BMI, and longer duration of disease could be considered at high-risk for developing MASLD.

Effects of COVID-19 on diabetes care among dutch diabetes outpatients

AIMS

The COVID-19 pandemic impacted diabetes care by reducing diabetes outpatient visits and diabetes-related screening due to allocation of healthcare resources. Yet the impact of COVID-19 on diabetes outpatients has not been extensively evaluated. This study aimed to assess the effect of the COVID-19 pandemic on diagnostics and intermediate outcomes of outpatient diabetes care pre- and during COVID.

METHODS

This observational cohort study included 8,442 diabetes patients in the Dutch Pediatric and Adult Registry of Diabetes (DPARD) visiting diabetes outpatient clinics in 2019 and 2021. A mixed-effects regression analysis was used to examine differences in target achievement of HbA1c, BMI, blood pressure, LDL-cholesterol, eGFR, and the difference in mean HbA1c between 2019 and 2020 among n = 1,426 outpatients who visited in both years. Analyses were adjusted for age, sex, and BMI.

RESULTS

A 22.7% (21.6-23.8%, p < 0.001) decline in outpatient volume was observed during the pandemic (2020). BMI, lipid spectrum, kidney function, and HbA1c were assessed less frequently in 2020 than in 2019. In 2020, compared to 2019, the median HbA1c level increased by 2.2% (1.0 mmol/mol, p = 0.035) and the percentages of patients with known HbA1C meeting targets below 10, 8, 7% (86, 64, and 53 mmol/mol) decreased by 0.5%, 1.7% and 1.4%, respectively. Target blood pressure ≤ 130/80 mmHg was achieved more often in 2020 (15.0% versus 18.3%, p = 0.018), while HbA1c ≤ 86 mmol/mol was achieved less (89.3% versus 87.1%, p = 0.001), among diabetes outpatients seen in both 2019 and 2020. In patients visiting both years, HbA1c was 2.3% (1.9 mmol/l, 95% CI 1.2-2.5, p < 0.001) lower during the pandemic than in the prepandemic (2019).

CONCLUSIONS

The COVID pandemic was associated with a marked reduction in patient volume in diabetes outpatient care among five hospitals. Among patients who received outpatient care both before and during the pandemic period, HbA1c control and blood pressure control enhanced during the pandemic. Re-evaluation of current diabetes outpatient care organization is warranted to ensure optimal diabetes care in future times.