Abnormal coagulation and enhanced fibrinolysis due to lysinuric protein intolerance associates with bleeds and renal impairment

INTRODUCTION

Lysinuric protein intolerance (LPI), a rare autosomal recessive transport disorder of cationic amino acids lysine, arginine and ornithine, affects intestines, lungs, liver and kidneys. LPI patients may display potentially life-threatening bleeding events, which are poorly understood.

AIMS

To characterize alterations in haemostatic and fibrinolytic variables associated with LPI.

METHODS

We enrolled 15 adult patients (8 female) and assessed the clinical ISTH/SSC-BAT bleeding score (BS). A variety of metabolic and coagulation assays, including fibrin generation test derivatives, clotting time (CT) and clot lysis time (CLT), thromboelastometry (ROTEM), and PFA-100 and Calibrated Automated Thrombogram (CAT), were used.

RESULTS

All patients had mild-to-moderate renal insufficiency, and moderate bleeding tendency (BS 4) without spontaneous bleeds. Mild anaemia and thrombocytopenia occurred. Traditional clotting times were normal, but in contrast, CT in fibrin generation test, and especially ROTEM FIBTEM was abnormal. The patients showed impaired primary haemostasis in PFA, irrespective of normal von Willebrand factor activity, but together with lowered fibrinogen and FXIII. Thrombin generation (TG) was reduced in vitro, according to CAT-derived endogenous thrombin potential, but in vivo TG was enhanced in the form of circulating prothrombin fragment 1 and 2 values. Very high D-dimer and plasmin-α2-antiplasmin (PAP) complex levels coincided with shortened CLT in vitro.

CONCLUSIONS

Defective primary haemostasis, coagulopathy, fibrin abnormality (FIBTEM, CT and CLT), low TG in vitro and clearly augmented fibrinolysis (PAP and D-dimer) in vivo were all detected in LPI. Altered fibrin generation and hyperfibrinolysis were associated with the metabolic and renal defect, suggesting a pathogenetic link in LPI.

Effect of Dietary Counseling on a Comprehensive Metabolic Profile from Childhood to Adulthood

OBJECTIVES

To study the effects of repeated, infancy-onset dietary counseling on a detailed metabolic profile. Effects of dietary saturated fat replacement on circulating concentrations of metabolic biomarkers still remain unknown.

STUDY DESIGN

The Special Turku Coronary Risk Factor Intervention Project (STRIP) study is a longitudinal, randomized atherosclerosis prevention trial in which repeated dietary counseling aimed at reducing the proportion of saturated fat intake. Nuclear magnetic resonance metabolomics quantified circulating metabolites from serum samples assessed at age 9 (n = 554), 11 (n = 553), 13 (n = 508), 15 (n = 517), 17 (n = 457), and 19 (n = 417) years.

RESULTS

The intervention reduced dietary intake of saturated fat (mean difference in daily percentage of total energy intake: -2.1 [95% CI -1.9 to -2.3]) and increased intake of polyunsaturated fat (0.6 [0.5-0.7]). The dietary counseling intervention led to greater serum proportions of polyunsaturated fatty acids (P < .001), with greater proportions of both circulating omega-3 (P = .02) and omega-6 (P < .001) fatty acids. The proportion of saturated fatty acids in serum was lower for both boys and girls in the intervention group (P < .001), whereas the serum proportion of monounsaturated fat was lower for boys in the intervention group only (P < .001). The intervention also reduced circulating intermediate-density lipoprotein and low-density lipoprotein lipid concentrations (P < .01). Dietary intervention effects on nonlipid biomarkers were minor except from greater concentrations of glutamine in the intervention group.

CONCLUSIONS

Repeated dietary counseling from infancy to early adulthood yielded favorable effects on multiple circulating fatty acids and lipoprotein subclass lipids, particularly in boys. These molecular effects substantiate the beneficial role of saturated fat replacement on the metabolic risk profile.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00223600.

Maternal and fetal genetic contribution to gestational weight gain

BACKGROUND

Clinical recommendations to limit gestational weight gain (GWG) imply high GWG is causally related to adverse outcomes in mother or offspring, but GWG is the sum of several inter-related complex phenotypes (maternal fat deposition and vascular expansion, placenta, amniotic fluid and fetal growth). Understanding the genetic contribution to GWG could help clarify the potential effect of its different components on maternal and offspring health. Here we explore the genetic contribution to total, early and late GWG.

PARTICIPANTS AND METHODS

A genome-wide association study was used to identify maternal and fetal variants contributing to GWG in up to 10 543 mothers and 16 317 offspring of European origin, with replication in 10 660 mothers and 7561 offspring. Additional analyses determined the proportion of variability in GWG from maternal and fetal common genetic variants and the overlap of established genome-wide significant variants for phenotypes relevant to GWG (for example, maternal body mass index (BMI) and glucose, birth weight).

RESULTS

Approximately 20% of the variability in GWG was tagged by common maternal genetic variants, and the fetal genome made a surprisingly minor contribution to explain variation in GWG. Variants near the pregnancy-specific beta-1 glycoprotein 5 (PSG5) gene reached genome-wide significance (P=1.71 × 10-8) for total GWG in the offspring genome, but did not replicate. Some established variants associated with increased BMI, fasting glucose and type 2 diabetes were associated with lower early, and higher later GWG. Maternal variants related to higher systolic blood pressure were related to lower late GWG. Established maternal and fetal birth weight variants were largely unrelated to GWG.

CONCLUSIONS

We found a modest contribution of maternal common variants to GWG and some overlap of maternal BMI, glucose and type 2 diabetes variants with GWG. These findings suggest that associations between GWG and later offspring/maternal outcomes may be due to the relationship of maternal BMI and diabetes with GWG.

Longitudinal child-oriented dietary intervention: Association with parental diet and cardio-metabolic risk factors. The Special Turku Coronary Risk Factor Intervention Project

Background The child-oriented dietary intervention given in the prospective Special Turku Coronary Risk Factor Intervention Project (STRIP) has decreased the intake of saturated fat and lowered serum cholesterol concentration in children from infancy until early adulthood. In this study, we investigated whether the uniquely long-term child-oriented intervention has affected also secondarily parental diet and cardio-metabolic risk factors. Methods The STRIP study is a longitudinal, randomized infancy-onset atherosclerosis prevention trial continued from the child's age of 8 months to 20 years. The main aim was to modify the child's diet towards reduced intake of saturated fat. Parental dietary intake assessed by a one-day food record and cardio-metabolic risk factors were analysed between the child's ages of 9-19 years. Results Saturated fat intake of parents in the intervention group was lower [mothers: 12.0 versus 13.9 daily energy (E%), p < 0.0001; fathers: 12.5 versus 13.9 E%, p < 0.0001] and polyunsaturated fat intake was higher (mothers: 6.1 versus 5.4 E%, p < 0.0001; fathers: 6.3 versus 5.9 E%, p = 0.0003) compared with the control parents. Maternal total and low-density lipoprotein cholesterol concentrations were lower in the intervention compared with the control group (mean ± SE 5.02 ± 0.04 versus 5.14 ± 0.04 mmol/l, p = 0.04 and 3.19 ± 0.04 versus 3.30 ± 0.03 mmol/l, p = 0.03, respectively). Paternal cholesterol values did not differ between the intervention and control groups. Other cardio-metabolic risk factors were similar in the study groups. Conclusions Child-oriented dietary intervention shifted the dietary fat intakes of parents closer to the recommendations and tended to decrease total and low-density lipoprotein cholesterol in the intervention mothers. Dietary intervention directed to children benefits also parents.

Cardiometabolic Determinants of Carotid and Aortic Distensibility From Childhood to Early Adulthood

Children who are obese or have familial hypercholesterolemia have stiffer arteries compared with lean, healthy peers. Limited data are, however, available on the association of cardiometabolic risk markers and arterial distensibility in healthy children, particularly in a longitudinal setting. Therefore, we studied in the prospective STRIP (Special Turku Coronary Risk Factor Intervention Project) comprising healthy, predominantly normal weight participants the association of several cardiometabolic and dietary risk markers with arterial distensibility from childhood to early adulthood. Carotid and aortic distensibility (cdist, adist) was assessed repeatedly with ultrasonography at the age of 11, 13, 15, 17, and 19 years in the longitudinal atherosclerosis prevention study (n_cdist=420-503, n_adist=407-476). Data on cardiometabolic risk markers and diet were available since early childhood. In multivariable analyses, body mass index (β=-0.0019 [SE 0.0085]; P=0.037), systolic blood pressure (β=-0.0025 [SE 0.00065]; P=0.0001), low-density lipoprotein cholesterol (β=-0.026 [SE 0.012]; P=0.034), and homeostasis model of insulin resistance (β=-0.048 [SE 0.018]; P=0.0071) were independently associated with carotid distensibility. Systolic blood pressure (β=-0.0069 [SE 0.00097]; P<0.0001) and low-density lipoprotein cholesterol (β=-0.039 [SE 0.018]; P=0.031) associated independently with aortic distensibility. Dietary variables were not independently associated with arterial distensibility. Participants with low arterial distensibility had higher body mass index (P_cdist=0.0090, P_adist=0.098) and higher systolic (P_cdist<0.0001, P_adist<0.0001) and diastolic blood pressures (P_cdist<0.0001, P_adist=0.0002) already from early childhood. Body mass index, blood pressure, low-density lipoprotein cholesterol, and homeostasis model of insulin resistance identified since childhood associate with arterial distensibility in healthy children and adolescents. These data support the relevance of these factors as part of primordial prevention.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00223600.

Genetic risk clustering increases children's body weight at 2 years of age - the STEPS Study

BACKGROUND

Genetic determinants have an impact on adult weight but the association between genetic determinants and weight at young age is still poorly understood.

OBJECTIVE

The objective of this study was to examine the association between genetic risk scores and early growth from birth to 2 years of age.

METHODS

Genetic risk scores of 83 adiposity-related or obesity-related single nucleotide polymorphisms (SNPs) (genetic risk score [GRS]83) were calculated for 1278 children. Specific phenotype score for 16 weight-related SNPs (weightGRS) was calculated. Anthropometric data were obtained at birth, 13 months and 2 years of age.

RESULTS

The GRS83 was associated with weight at 13 months (β = 0.080, P = 0.015) and 2 years (β = 0.080, P = 0.017) of age and with weight gain from birth to 13 months (β = 0.069, P = 0.036) and to 2 years of age (β = 0.074, P = 0.028). At 2 years of age, the GRS83 was also associated with weight for height (β = 0.065, P = 0.046), weight-for-height standard deviation score (SDS) (β = 0.074, P = 0.022) and body mass index SDS (β = 0.068, P = 0.045). WeightGRS was associated with higher body weight at 13 months (β = 0.081, P = 0.014) and 2 years of age (β = 0.086, P = 0.011). The genetic effect on weight varied from 0.69 to 1.89 kg at 2 years of age according to number of risk alleles. Children with high genetic risk for adiposity were heavier than children with low genetic risk at 2 years of age (12.8 vs. 13.4 kg, P = 0.017).

CONCLUSION

The GRS 83 revealed increased genetic risk for higher weight in children already at 13 months and 2 years of age, which may result in increased obesity risk later in life.

Genome-wide associations for birth weight and correlations with adult disease

Birth weight (BW) has been shown to be influenced by both fetal and maternal factors and in observational studies is reproducibly associated with future risk of adult metabolic diseases including type 2 diabetes (T2D) and cardiovascular disease. These life-course associations have often been attributed to the impact of an adverse early life environment. Here, we performed a multi-ancestry genome-wide association study (GWAS) meta-analysis of BW in 153,781 individuals, identifying 60 loci where fetal genotype was associated with BW (P < 5 × 10-8). Overall, approximately 15% of variance in BW was captured by assays of fetal genetic variation. Using genetic association alone, we found strong inverse genetic correlations between BW and systolic blood pressure (Rg = -0.22, P = 5.5 × 10-13), T2D (Rg = -0.27, P = 1.1 × 10-6) and coronary artery disease (Rg = -0.30, P = 6.5 × 10-9). In addition, using large -cohort datasets, we demonstrated that genetic factors were the major contributor to the negative covariance between BW and future cardiometabolic risk. Pathway analyses indicated that the protein products of genes within BW-associated regions were enriched for diverse processes including insulin signalling, glucose homeostasis, glycogen biosynthesis and chromatin remodelling. There was also enrichment of associations with BW in known imprinted regions (P = 1.9 × 10-4). We demonstrate that life-course associations between early growth phenotypes and adult cardiometabolic disease are in part the result of shared genetic effects and identify some of the pathways through which these causal genetic effects are mediated.

Imbalance of plasma amino acids, metabolites and lipids in patients with lysinuric protein intolerance (LPI)

BACKGROUND

Lysinuric protein intolerance (LPI [MIM 222700]) is an aminoaciduria with defective transport of cationic amino acids in epithelial cells in the small intestine and proximal kidney tubules due to mutations in the SLC7A7 gene. LPI is characterized by protein malnutrition, failure to thrive and hyperammonemia. Many patients also suffer from combined hyperlipidemia and chronic kidney disease (CKD) with an unknown etiology.

METHODS

Here, we studied the plasma metabolomes of the Finnish LPI patients (n=26) and healthy control individuals (n=19) using a targeted platform for analysis of amino acids as well as two analytical platforms with comprehensive coverage of molecular lipids and polar metabolites.

RESULTS

Our results demonstrated that LPI patients have a dichotomy of amino acid profiles, with both decreased essential and increased non-essential amino acids. Altered levels of metabolites participating in pathways such as sugar, energy, amino acid and lipid metabolism were observed. Furthermore, of these metabolites, myo-inositol, threonic acid, 2,5-furandicarboxylic acid, galactaric acid, 4-hydroxyphenylacetic acid, indole-3-acetic acid and beta-aminoisobutyric acid associated significantly (P<0.001) with the CKD status. Lipid analysis showed reduced levels of phosphatidylcholines and elevated levels of triacylglycerols, of which long-chain triacylglycerols associated (P<0.01) with CKD.

CONCLUSIONS

This study revealed an amino acid imbalance affecting the basic cellular metabolism, disturbances in plasma lipid composition suggesting hepatic steatosis and fibrosis and novel metabolites correlating with CKD in LPI. In addition, the CKD-associated metabolite profile along with increased nitrite plasma levels suggests that LPI may be characterized by increased oxidative stress and apoptosis, altered microbial metabolism in the intestine and uremic toxicity.

Home-Based Exercise Training Improves Left Ventricle Diastolic Function in Survivors of Childhood ALL: A Tissue Doppler and Velocity Vector Imaging Study

BACKGROUND

Advanced echocardiographic methods may reveal signs of late anthracycline cardiac toxicity (ACT) even in asymptomatic patients. We studied echocardiographic tissue Doppler imaging (TDI) and velocity vector imaging (VVI) in long-term survivors of childhood acute lymphoblastic leukemia (ALL) before and after an exercise intervention.

METHODS

Twenty-one asymptomatic, anthracycline-treated, long-term childhood ALL survivors with matched controls were studied at baseline. Seventeen of the survivors participated in a 3-month home-based exercise program. Echocardiography with TDI and VVI was performed.

RESULTS

At baseline, ejection fraction (60.7 ± 4.7% vs. 62.3 ± 3.7%, P = 0.22) and fractional shortening (32.6 ± 3.1% vs. 34.0 ± 2.8%, P = 0.13) were similar in survivors and controls. Lateral early diastolic mitral annulus velocity E' (32.81 ± 5.71 cm/sec vs. 38.03 ± 6.21 cm/sec, P = 0.01), E'/A' (1.60 ± 0.48 vs. 2.07 ± 0.63, P = 0.01), and E/E' (2.78 ± 0.35 vs. 2.42 ± 0.62, P = 0.04) were impaired compared to controls. Peak circumferential strain and strain rate were attenuated at apex (-24.50 ± 3.46% vs. -28.06 ± 4.39%, P = 0.01 and -1.47 ± 0.22 sec(-1) vs. -1.68 ± 0.33 sec(-1) , P = 0.02) compared to controls. After the intervention, early diastolic mitral inflow velocity E (87.76 ± 12.54 cm/s vs. 95.28 ± 10.48 cm/s, P = 0.04) and E' increased (31.78 ± 5.50 cm/s vs. 34.96 ± 5.41 cm/s, P < 0.01). Peak circumferential systolic and diastolic strain rates at mid-level (-1.22 ± 0.21 sec(-1) vs. -1.35 ± 0.24 sec(-1) , P = 0.04 and 1.25 ± 0.25 sec(-1) vs. 1.48 ± 0.35 sec(-1) , P < 0.01) improved after the exercise program.

CONCLUSIONS

A simple home-based exercise program improved cardiac function in asymptomatic childhood ALL survivors. Adding TDI in routine echocardiographic examination may improve the recognition of early signs of ACT, and VVI may bring additional information. The improvements in cardiac function after the exercise program emphasize the importance of physical activity in this population.

High sucrose intake at 3 years of age is associated with increased salivary counts of mutans streptococci and lactobacilli, and with increased caries rate from 3 to 16 years of age

OBJECTIVE

We aimed to study the long-term associations between sucrose intake (SI), selected representatives of the cariogenic oral flora, and the dental health of children from 3 to 16 years of age.

METHODS

At 7 months of age 1,062 infants (540 intervention; 522 controls) were included in the prospective, randomised STRIP-project aimed at restricting the child's saturated fat and cholesterol intake to prevent atherosclerosis when they become adults. At 3 years of age, every fifth child was invited (n = 178) to an oral sub-study, and 148 (78 boys) children attended. A restudy was conducted on 135 children aged 6, 127 aged 9, 114 aged 12 and 88 aged 16. SI using 4-day food records, plate-cultured mutans streptococci (MS), salivary lactobacilli (LB) and yeasts using commercial kits (Orion Diagnostica, Espoo Finland), toothbrushing frequency using fluoridated toothpaste and dental health expressed as d 3 mft/D 3 MFT were regularly recorded.

RESULTS

The SI of children whose intake was ≥ 10 E% (high SI) at 3 years remained high throughout the entire follow-up (p < 0.001, GLM for repeated measures) period, and they had higher salivary MS and LB counts (p = 0.024 and p = 0.068, respectively, GLM) than their counterparts whose SI was below 10 E% (low SI). No differences in toothbrushing habits were found between the high and low SI-groups. Caries-survival was strongly associated with low 6-year-counts of MS (p = 0.008, Cox regression analysis), and the d 3 mft/D 3 MFTscores of the high SI-group were higher than those of the low SI-group (p = 0.046, GLM).

CONCLUSIONS

High SI at 3 years was associated with high MS-counts ( ≥ 10 5 cfu/ml) and with a high risk for caries.

Initiation and exclusivity of breastfeeding: association with mothers' and fathers' prenatal and postnatal depression and marital distress

INTRODUCTION

This study explored the effects of mothers' and fathers' prenatal and postnatal depressive symptoms and marital distress on breastfeeding initiation and exclusive breastfeeding (EBF) duration.

MATERIAL AND METHODS

This was a prospective follow-up of a cohort sample of 873 families participating to an intensive follow-up cohort of longitudinal Steps to the Healthy Development and Well-being of Children study (The STEPS study) in Southwestern Finland. The depressive symptoms were evaluated by The Edinburgh Postpartum Depression Scale and marital distress by the Revised Dyadic Adjustment Scale at 20th gestational week and at 4 months postpartum. EBF was self-reported real-time and defined as an infant receiving no food or drink other than mother's breast milk since birth, except occasionally water.

RESULTS

Neither parents' prenatal depressive symptoms predicted breastfeeding initiation or EBF duration. The mothers' prenatal depressive symptoms, in turn, predicted their postnatal depressive symptoms, which were associated with shorter duration of EBF. The EBF duration was shortest amongst the mothers who had depressive symptoms both pre- and postnatally compared to mothers who had depressive symptoms only in either time point alone (M = 1.54, 2.06 and 2.04 months, respectively). Higher prenatal maternal marital distress was associated with longer EBF duration.

CONCLUSIONS

The findings suggest that the continuity of maternal depressive symptoms throughout the perinatal period has adverse effect on EBF duration. Identification and treatment of mothers' depressive symptoms already during the prenatal period may improve breastfeeding practices. The finding of mothers' marital distress having positive impact on breastfeeding practices requires further investigation.

[Congenital disorder of glycosylation type Ia (CDG Ia) - underdiagnosed entity?]

Congenital disorders of glycosylation (CDG) are a relatively recently identified group of multisystem disorders caused by defective glycosylation of N-glycosylated proteins. They mainly involve the central and peripheral nervous system, but other organ systems are involved as well. Type CDG Ia accounts for over 80% of cases, characterized by decreased activity of the enzyme phosphomannomutase caused by mutations in chromosome 16 PMM2 gene. Treatment of CDG Ia remains symptomatic.

Association of Adiponectin with Adolescent Cardiovascular Health in a Dietary Intervention Study

OBJECTIVE

To investigate whether an infancy-onset, low saturated fat-oriented dietary intervention influences serum adiponectin concentration in adolescents, and to study the association of adiponectin with subclinical markers of vascular health, and cardio-metabolic risk factors.

STUDY DESIGN

The longitudinal, randomized Special Turku Coronary Risk Factor Intervention Project aimed to modify child's dietary fat quality replacing saturated fat with unsaturated fat. Serum adiponectin (n = 521) along with weight, height, high-density lipoprotein cholesterol, C-reactive protein (CRP), triglycerides, and insulin were measured at age 15 years. Adiposity was assessed using body mass index, waist circumference, and abdominal fat thickness measured with ultrasound. Metabolic syndrome was defined according to International Diabetes Foundation criteria. Vascular ultrasound measures including carotid intima-media thickness (IMT) were assessed.

RESULTS

Adiponectin concentrations were similar in the intervention and control groups (P = .16). Adiponectin associated with carotid IMT (r = -0.13, P = .005), high-density lipoprotein cholesterol (r = 0.18, P < .0001), triglycerides (r = -0.16, P = .0004), CRP (r = -0.10, P = .02), insulin (r = -0.14, P = .002), and adiposity (r = -0.18-0.24, P ≤ .0001). When adjusted for adiposity indices, the association with carotid IMT was only marginally diluted (P = .03-.06), but the associations with insulin and CRP became nonsignificant. Adolescents with adiponectin ≤median had 4-fold risk of metabolic syndrome than peers with adiponectin >median (CI 1.8-10.2, P = .0001).

CONCLUSIONS

In healthy adolescents, low serum adiponectin is related with carotid IMT and metabolic syndrome. We found no evidence that repeated low saturated fat-oriented dietary counseling would influence serum adiponectin in adolescence.

TRIAL REGISTRATION

Registered with ClinicalTrials.gov: NCT00223600.

Psychological wellbeing in 20-year-old adults receiving repeated lifestyle counselling since infancy

AIM

This study examined whether there was an association between a repeated dietary and lifestyle intervention that began in infancy and participants' psychological wellbeing at the age of 20.

METHODS

We examined the psychological wellbeing of 457 young adults participating in the Special Turku Coronary Risk Factor Intervention Project (STRIP), a randomised controlled trial conducted in Finland between 1989 and 2011. We assessed potential differences in psychological wellbeing between the intervention and control groups by examining participants' satisfaction with life, how they rated their health, their experiences of stress and the consequences of experiencing stress and symptoms of depression at the age of 20. We also assessed socio-economic status during childhood as a potential confounding factor.

RESULTS

We found no association between the long-term dietary and lifestyle intervention and participants' psychological wellbeing in adulthood. Adjusting for sex and childhood socio-economic status did not affect the results and socio-economic status did not moderate the association between the intervention and psychological wellbeing.

CONCLUSION

Our findings showed no association between intensive dietary and lifestyle counselling that was initiated in infancy with psychological wellbeing in adulthood and the initiative did not appear to pose any psychological risks.

Dysfunction in macrophage toll-like receptor signaling caused by an inborn error of cationic amino acid transport

Amino acids, especially arginine, are vital for the well-being and activity of immune cells, and disruption of amino acid balance may weaken immunity and predispose to infectious and autoimmune diseases. We present here a model of an inborn aminoaciduria, lysinuric protein intolerance (LPI), in which a single mutation in y(+)LAT1 cationic amino acid transporter gene SLC7A7 leads to a multisystem disease characterized by immunological complications, life-threatening pulmonary alveolar proteinosis and nephropathy. Macrophages are suggested to play a central role in LPI in the development of these severe secondary symptoms. We thus studied the effect of the Finnish y(+)LAT1 mutation on monocyte-derived macrophages where toll-like receptors (TLRs) act as the key molecules in innate immune response against external pathogens. The function of LPI patient and control macrophage TLR signaling was examined by stimulating the TLR2/1, TLR4 and TLR9 pathways with their associated pathogen-associated molecular patterns. Downregulation in expression of TLR9, IRF7, IRF3 and IFNB1 and in secretion of IFN-α was detected, suggesting an impaired response to TLR9 stimulation. In addition, secretion of TNF-α, IL-12 and IL-1RA by TLR2/1 stimulation and IL-12 and IL-1RA by TLR4 stimulation was increased in the LPI patients. LPI macrophages secreted significantly less nitric oxide than control macrophages, whereas plasma concentrations of inflammatory chemokines CXCL8, CXCL9 and CXCL10 were elevated in the LPI patients. In conclusion, our results strengthen the relevance of macrophages in the pathogenesis of LPI and, furthermore, suggest that cationic amino acid transport plays an important role in the regulation of innate immune responses.

Urine Beta2-Microglobulin Is an Early Marker of Renal Involvement in LPI

OBJECTIVE

Lysinuric protein intolerance (LPI) is a rare autosomal recessive disorder affecting the transport of cationic amino acids. It has previously been shown that approximately one third of the Finnish LPI patients have impaired renal function. The aim of this study was to analyse in detail urine beta2-microglobulin values, renal dysfunction, oral L-citrulline doses and plasma citrulline concentrations in Finnish LPI patients.

METHODS AND RESULTS

Of the 41 Finnish LPI patients, 56% had proteinuria and 53% hematuria. Mean plasma creatinine concentration was elevated in 48%, serum cystatin C in 62%, and urine beta2-microglobulin in 90% of the patients. Seventeen per cent of the patients developed ESRD, and five of them received a kidney transplant. L-citrulline doses and fasting plasma citrulline concentrations were similar in adult LPI patients with decreased and normal GFR (mean ± SD 79.5 ± 29.2 vs. 82.4 ± 21.9 mg/kg/day, P = 0.619, and 80.3 ± 20.1 vs. 64.8 ± 23.0 μmol/l, P = 0.362, respectively).

CONCLUSIONS

Urine beta2-microglobulin is a sensitive early marker of renal involvement, and it should be monitored regularly in LPI patients. Weight-based oral L-citrulline doses and plasma citrulline concentrations were not associated with renal function. LPI patients with ESRD were successfully treated with dialysis and kidney transplantation.

The association of dietary alpha-linolenic acid with blood pressure and subclinical atherosclerosis in people born small for gestational age: the Special Turku Coronary Risk Factor Intervention Project study

OBJECTIVE

To determine whether dietary alpha-linolenic (omega-3) fatty acid intake is associated with lower blood pressure and aortic intima-media thickness (IMT) in people born small for gestational age (SGA).

STUDY DESIGN

Participants were recruited at age 6 months and followed up every 6-12 months until age 19 years. Blood pressure and food records were assessed at each visit. A total of 1009 participants had at least one blood pressure measure and complete birth weight and gestational age data, including 115 (11%) born SGA (birth weight≤10th percentile). Aortic IMT was assessed by ultrasound at 19 years (n=413). Analysis was by linear mixed models and multivariable linear regression.

RESULTS

Children born SGA had greater systolic and pulse pressure from age 14 years onwards. In those born SGA, systolic blood pressure was 2.1 mm Hg lower ([95% CI 0.8-3.3]; P=.001) and pulse pressure 1.4 mm Hg lower ([95% CI 0.3-2.4]; P=.01), per exponential increase in alpha-linolenic acid (ALA) intake; weakened by adjustment for anthropometric measures. Long-term ALA intake was inversely associated with aortic IMT at 19 years in those born SGA (-0.30 mm [95% CI -0.52, -0.08] per exponential greater ALA intake; P=.008), independent of other dietary and anthropometric factors.

CONCLUSION

Long-term dietary ALA intake during childhood is associated with improved vascular health in people born SGA.

A novel common variant in DCST2 is associated with length in early life and height in adulthood

Common genetic variants have been identified for adult height, but not much is known about the genetics of skeletal growth in early life. To identify common genetic variants that influence fetal skeletal growth, we meta-analyzed 22 genome-wide association studies (Stage 1; N = 28 459). We identified seven independent top single nucleotide polymorphisms (SNPs) (P < 1 × 10(-6)) for birth length, of which three were novel and four were in or near loci known to be associated with adult height (LCORL, PTCH1, GPR126 and HMGA2). The three novel SNPs were followed-up in nine replication studies (Stage 2; N = 11 995), with rs905938 in DC-STAMP domain containing 2 (DCST2) genome-wide significantly associated with birth length in a joint analysis (Stages 1 + 2; β = 0.046, SE = 0.008, P = 2.46 × 10(-8), explained variance = 0.05%). Rs905938 was also associated with infant length (N = 28 228; P = 5.54 × 10(-4)) and adult height (N = 127 513; P = 1.45 × 10(-5)). DCST2 is a DC-STAMP-like protein family member and DC-STAMP is an osteoclast cell-fusion regulator. Polygenic scores based on 180 SNPs previously associated with human adult stature explained 0.13% of variance in birth length. The same SNPs explained 2.95% of the variance of infant length. Of the 180 known adult height loci, 11 were genome-wide significantly associated with infant length (SF3B4, LCORL, SPAG17, C6orf173, PTCH1, GDF5, ZNFX1, HHIP, ACAN, HLA locus and HMGA2). This study highlights that common variation in DCST2 influences variation in early growth and adult height.

Metabolic syndrome from adolescence to early adulthood: effect of infancy-onset dietary counseling of low saturated fat: the Special Turku Coronary Risk Factor Intervention Project (STRIP)

BACKGROUND

Adolescent metabolic syndrome (MetS) predicts type 2 diabetes mellitus and subclinical atherosclerosis in adulthood. Our aim was to establish the relationship between an infancy-onset dietary intervention and risk of having MetS between 15 and 20 years of age.

METHODS AND RESULTS

The Special Turku Coronary Risk Factor Intervention Project for Children (STRIP) study is a longitudinal, randomized atherosclerosis prevention trial in which repeated dietary counseling aiming at reducing intake of saturated fat took place from infancy to early adulthood. Participants who had complete data on the MetS components (waist circumference, blood pressure, triglycerides, glucose, high-density lipoprotein cholesterol) at 15 (n=512), 16 (n=485), 17 (n=475), 18 (n=459), 19 (n=439), and 20 (n=407) years of age were included in the study. Modified International Diabetes Foundation criteria with 80th/20th percentile cutoff points for the components were primarily applied in statistical analyses, and the results were replicated with the use of other pediatric MetS definitions. Between the ages of 15 and 20 years, the prevalence of MetS varied between 6.0% and 7.5% in participants in the intervention group and between 10% and 14% in the control group. The long-term relative risk of MetS was significantly lower in the intervention group (relative risk, 0.59; 95% confidence interval, 0.40-0.88; P=0.009). Of the individual MetS components, the intervention decreased risk of high blood pressure in both sexes (relative risk, 0.83; 95% confidence interval, 0.70-0.99) and high triglycerides in male subjects (relative risk, 0.71; 95% confidence interval, 0.52-0.98). A statistically nonsignificant reduction was seen in the risk of high waist circumference in the intervention individuals (relative risk, 0.78; 95% confidence interval, 0.59-1.03).

CONCLUSION

Repeated infancy-onset dietary intervention is effective in the prevention of MetS in adolescence.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00223600.

Distensibility of the Aorta and Carotid Artery and Left Ventricular Mass From Childhood to Early Adulthood

Abstract—

In adults, arterial distensibility decreases with age and relates to changes in cardiac left ventricular mass. Longitudinal data on changes in arterial distensibility from childhood to adulthood are lacking. Our aim was to study the effect of age and sex, and low-saturated fat dietary counseling on arterial distensibility from childhood to early adulthood. In addition, we assessed the association of arterial distensibility with left ventricular mass. Distensibility of the abdominal aorta and common carotid artery was measured repeatedly at ages 11, 13, 15, 17, and 19 years (n=395–472) in an atherosclerosis prevention trial (Special Turku Coronary Risk Factor Intervention Project [STRIP]). Aortic and carotid distensibility decreased with age (both P <0.0001). In boys, distensibility values were generally lower ( P <0.0001) and showed steeper decrease by age (age and sex interaction: both P <0.01). The low-saturated fat dietary counseling given in STRIP was not significantly associated with arterial distensibility. Left ventricular mass increased with age ( P <0.0001), and it was greater in boys ( P <0.0001). In conclusion, a marked age-related decrease in vascular distensibility was found already at this young age, and this decrease was more pronounced in boys than girls. The longitudinal progression of aortic and carotid distensibility was related with changes in left ventricular mass.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00223600.

Interactions between genetic variants and dietary lipid composition: effects on circulating LDL cholesterol in children

BACKGROUND

Elevated serum low-density lipoprotein (LDL) cholesterol is a predictor of cardiovascular disease events, and the quality of dietary fat is known to influence serum concentrations of LDL cholesterol in children. Interindividual differences in response to diet exist, but the underlying genetic factors remain largely unknown.

OBJECTIVE

We aimed to identify genetic variants that modify the variation in serum lipid response to dietary fat quality.

DESIGN

We used data from 2 longitudinal Finnish cohorts designed to study risk factors for cardiovascular diseases. Large-scale genotyping was performed with Metabochip in a long-term randomized controlled dietary intervention trial, the Special Turku Coronary Risk Factor Intervention Project (STRIP), for discovery of genetic polymorphisms. The observational Cardiovascular Risk in Young Finns Study (YFS) with genome-wide genetic data was used as a replication sample for the initial findings. Dietary records were used to calculate the ratio of unsaturated to saturated fats. Interaction models and multiple follow-ups were used in the analysis.

RESULTS

In the STRIP cohort, a variant within the PARK2 locus, rs9364628, showed moderate interaction with dietary fat quality and a consistent direction of effect in both scans on serum LDL-cholesterol concentration in children aged 5 and 7 y (P < 0.0084 and P < 0.0057, respectively). In the YFS cohort, we were unable to replicate the initial discovery signal, but rs12207186 within the PARK2 locus and dietary lipid quality had a stronger interaction effect on serum LDL-cholesterol concentration (P < 9.44 × 10(-5)) than did rs9364628 in children aged 6 y.

CONCLUSION

This genotyping study involving 2 cohorts of healthy Finnish children indicates a possible interaction between PARK2 variants and dietary fat quality on serum LDL-cholesterol concentration. This trial was registered at clinicaltrials.gov as NCT00223600.

Genome-wide association study of sexual maturation in males and females highlights a role for body mass and menarche loci in male puberty

Little is known about genes regulating male puberty. Further, while many identified pubertal timing variants associate with age at menarche, a late manifestation of puberty, and body mass, little is known about these variants' relationship to pubertal initiation or tempo. To address these questions, we performed genome-wide association meta-analysis in over 11 000 European samples with data on early pubertal traits, male genital and female breast development, measured by the Tanner scale. We report the first genome-wide significant locus for male sexual development upstream of myocardin-like 2 (MKL2) (P = 8.9 × 10(-9)), a menarche locus tagging a developmental pathway linking earlier puberty with reduced pubertal growth (P = 4.6 × 10(-5)) and short adult stature (p = 7.5 × 10(-6)) in both males and females. Furthermore, our results indicate that a proportion of menarche loci are important for pubertal initiation in both sexes. Consistent with epidemiological correlations between increased prepubertal body mass and earlier pubertal timing in girls, body mass index (BMI)-increasing alleles correlated with earlier breast development. In boys, some BMI-increasing alleles associated with earlier, and others with delayed, sexual development; these genetic results mimic the controversy in epidemiological studies, some of which show opposing correlations between prepubertal BMI and male puberty. Our results contribute to our understanding of the pubertal initiation program in both sexes and indicate that although mechanisms regulating pubertal onset in males and females may largely be shared, the relationship between body mass and pubertal timing in boys may be complex and requires further genetic studies.

[Prevention of cardiovascular diseases--the most recent recommendations from the United States]

The origins of cardiovascular diseases reside in the childhood. The prevention of these diseases should therefore also start at an early age. The US recommendation for promoting children's cardiac health encourages to pay attention to living habits - non-smoking, healthy eating and adequate physical exercise. The recommendation also proposes the measurement of lipids from all children at the age of about 10 years. This has provoked discussion for and against - what would be the benefits and drawbacks of general screening.