Associations of polygenic risk scores for preeclampsia and blood pressure with hypertensive disorders of pregnancy

BACKGROUND

Preexisting hypertension increases risk for preeclampsia. We examined whether a generic blood pressure polygenic risk score (BP-PRS), compared with a preeclampsia-specific polygenic risk score (PE-PRS), could better predict hypertensive disorders of pregnancy.

METHODS

Our study sample included 141 298 genotyped FinnGen study participants with at least one childbirth and followed from 1969 to 2021. We calculated PRSs for SBP and preeclampsia using summary statistics for greater than 1.1 million single nucleotide polymorphisms.

RESULTS

We observed 8488 cases of gestational hypertension (GHT) and 6643 cases of preeclampsia. BP-PRS was associated with GHT [multivariable-adjusted hazard ratio for 1SD increase in PRS (hazard ratio 1.38; 95% CI 1.35-1.41)] and preeclampsia (1.26, 1.23-1.29), respectively. The PE-PRS was also associated with GHT (1.16; 1.14-1.19) and preeclampsia (1.21, 1.18-1.24), but with statistically more modest magnitudes of effect (P = 0.01). The model c-statistic for preeclampsia improved when PE-PRS was added to clinical risk factors (P = 4.6 × 10-15). Additional increment in the c-statistic was observed when BP-PRS was added to a model already including both clinical risk factors and PE-PRS (P = 1.1 × 10-14).

CONCLUSION

BP-PRS is strongly associated with hypertensive disorders of pregnancy. Our current observations suggest that the BP-PRS could capture the genetic architecture of preeclampsia better than the current PE-PRSs. These findings also emphasize the common pathways in the development of all BP disorders. The clinical utility of a BP-PRS for preeclampsia prediction warrants further investigation.

Increased Risk of Preeclampsia in Women With a Genetic Predisposition to Elevated Blood Pressure

BACKGROUND

Preeclampsia causes significant maternal and perinatal morbidity. Genetic factors seem to affect the onset of the disease. We aimed to investigate whether the polygenic risk score for blood pressure (BP; BP-PRS) is associated with preeclampsia, its subtypes, and BP values during pregnancy.

METHODS

The analyses were performed in the FINNPEC study (Finnish Genetics of Pre-Eclampsia Consortium) cohort of 1514 preeclamptic and 983 control women. In a case-control setting, the data were divided into percentiles to compare women with high BP-PRS (HBP-PRS; >95th percentile) or low BP-PRS (≤5th percentile) to others. Furthermore, to evaluate the effect of BP-PRS on BP, we studied 3 cohorts: women with preeclampsia, hypertensive controls, and normotensive controls.

RESULTS

BP values were higher in women with HBP-PRS throughout the pregnancy. Preeclampsia was more common in women with HBP-PRS compared with others (71.8% and 60.1%, respectively; P=0.009), and women with low BP-PRS presented with preeclampsia less frequently than others (44.8% and 61.5%, respectively; P<0.001). HBP-PRS was associated with an increased risk for preeclampsia (odds ratio, 1.7 [95% CI, 1.1-2.5]). Furthermore, women with HBP-PRS presented with recurrent preeclampsia and preeclampsia with severe features more often.

CONCLUSIONS

Our results suggest that HBP-PRS is associated with an increased risk of preeclampsia, recurrent preeclampsia, and preeclampsia with severe features. Furthermore, women with HBP-PRS present higher BP values during pregnancy. The results strengthen the evidence pointing toward the role of genetic variants associated with BP regulation in the etiology of preeclampsia, especially its more severe forms.

Role of an automated screening tool for familial hypercholesterolemia in patients with premature coronary artery disease

Background and aims

To validate an automated screening tool for patients with premature coronary artery disease (CAD) and high total cholesterol or LDL-C levels and assess if it would provide clinicians with additional support in identifying patients with Familial Hypercholesterolemia (FH).

Methods

An IT-based automated screening tool based on coronary angiography data recorded in the KARDIO registry and laboratory values was validated among patients undergone coronary angiography in the Heart Hospital at Tampere University Hospital between 2007 and 2017 fulfilling the criteria of premature CAD (men <55 years and women <60 years) and history of high total cholesterol (>8 mmol/l) or LDL-cholesterol (>5 mmol/l) levels. Electronic health records were retrospectively analyzed to determine if these patients had been diagnosed with FH based on clinical features and whether genetic testing had been conducted.

Results

The automated screening tool identified 0.7% (211/28295) of all patients undergone coronary angiography and revealed history of high cholesterol in 8% (211/2678) of patients with premature CAD during the study period. Fifty-one percent (107/211) of these patients fulfilled the clinical criteria for probable/definite FH based on the Dutch Lipid Clinic Network (DLCN) criteria.None of the patients had been diagnosed with FH based on clinical criteria before or after diagnosis of CAD. Thirteen percent of patients (n = 14) with probable/definite FH had been tested for genetic mutations of FH before or after CAD, five (36%) of them having a pathogenic FH variant. Two patients were referred to cascade screening.

Conclusions

FH was underdiagnosed among the population studied. An automated screening tool in cardiac care could provide additional support for clinicians in diagnosing patients potentially having FH.

Two novel mutations in the DNAH11 gene in primary ciliary dyskinesia (CILD7) with considerable variety in the clinical and beating cilia phenotype

Background

Diagnosis of primary ciliary dyskinesia (PCD) still remains a challenge, especially with mutations in the Dynein Arm Heavy Chain 11 (DNAH11) gene. Classical diagnostic measures like Transmission Electron Microscopy (TEM) are not applicable for mutations in the DNAH11 gene since ultrastructural defects of the ciliary apparatus are absent. Novel mutations encoding for PCD appear all the time with considerable variation in the clinical picture, making it necessary to update data bases and guidelines for PCD diagnostics.

Methods

In this study we examined two unrelated, Finnish families with symptoms of PCD applying the clinical scoring system: Primary ciliary dyskinesia Rule (PICADAR), high speed video microscopy analysis (HSVMA) for ciliary movement, a commercially available gene panel analysis and nasal Nitric Oxide (nNO) measurements if applicable.

Results

Two, likely pathogenic variants in the DNAH11 gene (c.2341G > A, p. (Glu781Lys) ja c.7645 + 5G > A) were detected. In the first family, compound heterozygous mutations led to disease manifestation in two of 4 children, which showed a similar phenotype of cilia beating pattern but marked differences in disease severity. In the second family, all three children were homozygotes for the c.2341G > A p.(Glu781Lys) mutation and showed a similar degree of disease severity. However, the phenotype of cilia beating pattern was different ranging from stiff, static cilia to a hyperkinetic movement in one of these children.

Conclusions

In this study we describe two Finnish families with PCD, revealing two novel mutations in the DNAH11 gene which show considerable variety in the clinical and beating cilia phenotype. The results of this study show the clinician that PCD can be much milder than generally expected and diagnosis demands a combination of measures which are only successful in experienced hands. Chronic and repeatedly treated wet cough should raise suspicion of PCD, referring the patient for further diagnostics to a specialised PCD centre.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12881-020-01171-2.

PARE0035 WHAT IS YOUR HEALTH ACTION IN 2020?

Background:

At the turn of the year and decade, it is a time when magazine columns and social media channels are full of New Year’s resolutions. We are thinking about weight control, fewer kilos, healthier lifestyles, increased mobility, mental well-being, more time with family and friends, learning new things, etc. For many New Year’s resolution is related to well-being, often a healthier diet and exercise.

What if these promises were properly inspired? What if we encouraged people to make especially good decisions supporting musculoskeletal health and do good deeds?

The Finnish Rheumatism Association and its partners started this project to encourage people make health promoting new year resolutions and tell them publicly.

Objectives:

The aim of the project is to promote the musculoskeletal health of the population and to raise citizens’ awareness of musculoskeletal health and illness. The purpose of the project is to inspire people to make promises and do deeds to support of musculoskeletal health. The project utilized people’s tendency to make New Year’s resolutions.

Even small actions and everyday life changes are going in the right direction. Anyone can participate and have successful experience.

Methods:

The project is online atwww.tinjanhuoltamo.fiThe website briefly describes the background of the project. It includes links to additional information and reliable sources, and provides guidance on how people with RMD’s can have a healthier life.

The project utilized the social media and participants were encouraged to make #lpromise updates for various social media channels. Campaign started at the beginning of December 2019. The radio campaign focused on Christmas holidays. Promises were made for the New Year´s Eve and some of them during January.

We sent materials and tasks every week for online groups and email lists. Tinja’s Service Station acted as a personal trainer but online. We took advantage of a modern, interactive online environment where people shared their habits and experiences.

All those who kept their promises till 2/29/2020 participated in a competition, where the prize was the winner’s choice of a welfare event, or a season ticket to a sports club or a local Rheumatism Organisation exercise group.

Results:

The Service Station turned out to be more interesting than expected. The Facebook group had 450 members and the email-group 75 people. The quantities exceeded our expectations.

Physical exercise attracted the promises most. Good second was nutrition.

Our social media campaign was not as successful as we had hoped for. It may be that people are too cautious of making public New Year’s Resolutions. The radio campaign managed to bring some more people to the email group, not so many for the Facebook group. It seemed a good idea to expand the campaign from social media to radio. The radio campaign reached people nationwide and there was a small peak in the Rheumatism Association website visits.

Conclusion:

This was quite nice and different project. It seemed that one act of health easily led to another and created a positive vicious circle. We start the project with good will and without blame. Changing one’s own activities and promoting future health require will and motivation. Motivation was the initiator of the action. A clear and realistic goal setting and a decision to reach the goal helped motivate.

At the end of the March we will sum up the final results and pick up good examples for musculoskeletal health actions. It is already certain that we will renew the project at the end of the year. A service station is a great low-threshold place where you can, in a good spirit, get support for your lifestyle changes.

Disclosure of Interests:

None declared

Follow-up study of the early, randomised paracetamol trial to preterm infants, found no adverse reactions at the two-years corrected age

AIM

We examined the long-term outcomes and safety of early intravenous paracetamol for ductus arteriosus closure at a corrected age of two years.

METHODS

This was a follow-up of the 2013-2014 randomised, double-blind Preterm Infant's Paracetamol Study at Oulu University Hospital, Finland, which recruited 48 very preterm infants within 24 hours of birth. They received intravenous paracetamol or a placebo for four days. In 2015-2017, we followed up 44 infants (92%) at two years of corrected age. This included clinical and neurodevelopmental assessments and a parental medical history questionnaire.

RESULTS

The 44 infants (55% boys) were born at 23⁵ -31⁶ weeks of gestation. No differences in the cardiac parameters, including blood pressures and ultrasound scan results, were found. Neurodevelopmental stages, as quantified by the Griffiths test, were similar. No signs of autism were reported. Asthma medication was more common in the control group, but the difference was not significant. Atopy scores, numbers of infections and the use of public health services were similar between the two groups.

CONCLUSION

No long-term adverse reactions of early intravenous paracetamol were detected two years later. Larger trials are needed on the safety and efficacy of paracetamol prophylaxis for early ductal closure in very preterm infants.

Intravenous paracetamol was associated with closure of the ductus arteriosus in extremely premature infants

AIM

Symptomatic patent ductus arteriosus may lead to serious complications in extremely preterm and extremely low birthweight infants and is often resistant to medication. We evaluated early intravenous paracetamol for pain prevention during respiratory therapy, in an attempt to understand the ductal treatment of such infants.

METHODS

Our cohort were 295 extremely preterm or extremely low birthweight infants, born at less than 28 weeks or 1000 g, respectively, who were treated in the neonatal intensive care unit of Oulu University Hospital from 2002 to 2015, before and after intravenous paracetamol was introduced in June 2009. Ductal closure dates, paracetamol medication details, morbidities and mortality data were evaluated.

RESULTS

Intravenous paracetamol was given to 128 infants, starting at a median of 4.4 hours age (range: 0-169 hours), with a mean total dosage of 212 mg/kg (range: 7.5-1175 mg/kg). We also included 167 controls who were mainly treated before we used intravenous paracetamol. Ibuprofen (p < 0.001) and ligation (p = 0.002) were lower in the paracetamol group than controls. No adverse effects were detected. Paracetamol was not associated with other morbidities.

CONCLUSION

We found that early use of intravenous paracetamol decreased the incidence of ductal therapies in extremely premature or extremely low birthweight infants.

Metformin should be considered in the treatment of gestational diabetes: a prospective randomised study

OBJECTIVE

To examine if oral metformin is as effective as insulin in the prevention of fetal macrosomy in pregnancies complicated with gestational diabetes mellitus (GDM).

DESIGN

Open-label prospective randomised controlled study.

SETTING

Maternity outpatient clinics in a secondary and tertiary level hospital in Finland.

SAMPLE

One hundred women with GDM who did not attain euglycaemia with diet.

METHODS

Women were randomised to therapy with insulin (n = 50) or oral metformin (n = 50).

MAIN OUTCOME MEASURES

Incidence of large-for-gestational-age (LGA) infants and neonatal morbidity.

RESULTS

There were no statistically significant differences in the incidence of LGA (8.5 versus 10.0%, P = 0.97), mean birthweight, mean cord artery pH or neonatal morbidity between the insulin and metformin groups. Fifteen (31.9%) of the 47 women randomised to metformin needed supplemental insulin. They were more obese (with a body mass index of 36 versus 30 kg/m(2), P = 0.002), had higher fasting blood glucose levels in an oral glucose tolerance test (6.1 versus 5.0 mmol/l, P = 0.001) and needed medical treatment for GDM earlier (26 versus 31 gestational weeks, P = 0.002) than women who were normoglycemic with metformin. There was a tendency to a higher rate of caesarean sections in the metformin group than in the insulin group (RR 1.9; 95% CI 0.99-3.71).

CONCLUSIONS

Metformin seems to be suitable for the prevention of fetal macrosomy, especially in lean or moderately overweight women developing GDM in late gestation. Women with considerable obesity, high fasting blood glucose and an early need for pharmacological treatment may be more suitable for insulin therapy.

Blood glucose level in preterm infants after antenatal exposure to glucocorticoid

AIM

To determine the impact of antenatal glucocorticoid on neonatal glucose homeostasis.

METHODS

This is a retrospective gestationally paired survey followed by a randomized study. On the basis of the interval between last antenatal dexamethasone and birth, 228 preterm infants born before 34 weeks were divided into Short (< 24 h), Intermediate (1-6 days), and Long (> or = 7 days) exposure groups and compared their gestationally paired controls. After a single course of betamethasone, the parturients remaining undelivered for one week were randomized to receive either one dose of betamethasone (n = 52) or placebo (n = 53). Glucose values were recorded at 11 time points in the first 3 days of life. Hypoglycaemic and hyperglycaemic values were counted.

RESULTS

There were no overall differences in mean glucose levels between the antenatal glucocorticoid and the control groups. However, the long exposure time to antenatal glucocorticoid was associated with increased risk of hyperglycaemia (OR 4.1; 2.2-7.6).

CONCLUSION

Antenatal glucocorticoid administration was associated with subtle disturbances of glucose homeostasis in preterm infants. These differences were dependent on the length of drug-delivery interval so that long exposition time seemed to increase the incidence of hyperglycaemia during the first days of life.

Polymorphisms of interleukin-6, hepatic lipase and calpain-10 genes, and preeclampsia

OBJECTIVE

We determined whether single nucleotide polymorphisms (SNPs) in interleukin-6 (IL-6), hepatic lipase (HL) and calpain-10 (CAPN-10) genes contribute to susceptibility to develop preeclampsia.

STUDY DESIGN

The study involved 133 preeclamptic and 115 healthy pregnant women who were genotyped for the C-174G polymorphism in the IL-6 gene, the G-250A polymorphism in the HL gene and SNP 43 (G/A) in the CAPN-10 gene. The chi2-test was used to assess genotype and allele frequency differences between the preeclamptic and control groups.

RESULTS

No significant differences were detected in genotype and allele distributions of the C-174G polymorphism in the IL-6 gene, between the preeclampsia and control groups (p=0.98 and 0.85, respectively). With respect to the G-250A polymorphism in the HL gene, the genotype and allele distributions were similar in both groups (p=0.64 and 0.48, respectively). The genotype and allele distributions of SNP 43 in the CAPN-10 gene also showed no statistical differences in the preeclampsia and control groups (p=0.73 and 0.45, respectively).

CONCLUSIONS

The C-174G polymorphism in the IL-6 gene, the G-250A polymorphism in the HL gene and SNP 43 (G/A) in the CAPN-10 gene are unlikely to be major genetic factors predisposing Finnish women to preeclampsia.

Adiponectin gene haplotype is associated with preeclampsia

We determined whether the polymorphism of the gene encoding adiponectin contributes to susceptibility to preeclampsia. The study involved 133 Finnish women with preeclampsia and 245 healthy control subjects. All women were genotyped for two single nucleotide polymorphisms (SNPs), SNP45 in exon 2 and SNP276 in intron 2, in the adiponectin gene. Chi2 analysis was used to assess genotype and allele frequency differences between the preeclamptic and control groups. In addition, the pair of loci haplotype analysis, using the expectation-maximization (EM) algorithm, was used to examine the estimated haplotype frequencies of the two SNPs, among the two groups. The TT genotype versus the pooled G genotypes in SNP276 was associated with protection against preeclampsia (p = 0.012) at an odds ratio of 0.27 (95% confidence interval [CI]: 0.09-0.80). Also the genotype and allele frequency distributions of SNP276 differed significantly between the preeclampsia group and the control group (p = 0.035 and p = 0.043, respectively). Single-point genotype and allele distributions in SNP45 of the adiponectin gene were not statistically different between the groups. In the haplotype estimation analysis, the pooled G haplotypes versus the TT haplotype were significantly overrepresented in the preeclampsia group (p = 0.042 +/- 0.005). Polymorphisms of the adiponectin gene show a weak, but statistically significant, haplotype association with susceptibility to preeclampsia in Finnish women.

Plasma Cell Membrane Glycoprotein-1 K121Q Polymorphism in Preeclampsia

BACKGROUND

Preeclampsia is a common hereditary disease with unclear aetiology and various genetic and environmental components. We wanted to determine whether genetic variability in the gene encoding plasma cell membrane glycoprotein-1 (PC-1) contributes to individual susceptibility to the development of preeclampsia.

METHODS

The case-control study involved 133 women with preeclampsia and 115 healthy controls. They were genotyped for the K121Q polymorphism in the PC-1 gene. chi(2) analysis was used to assess genotype and allele frequency differences between preeclamptic and control women.

RESULTS

The frequency of the PC-1 gene 121K allele was found to be equal in the two groups, being 90.2% among women with preeclampsia and 90.4% among controls (p = 0.937; OR = 1.024; 95% CI = 0.564-1.861). Also the genotype distribution of the PC-1 K121Q polymorphism was similar (p = 0.516) in the preeclamptic and control groups.

CONCLUSIONS

The K121Q polymorphism of the PC-1 gene is unlikely to be a major genetic factor predisposing to preeclampsia in Finnish women.

Preeclampsia and androgen receptor gene CAG repeat length: results from both children and women

PURPOSE

We studied whether the CAG (encoding glutamine) repeat length polymorphism in the first exon of the androgen receptor (AR) gene is predictive of preeclampsia.

METHODS

Fifty-nine children born after preeclamptic pregnancy (PRE) and 58 control subjects born after normotensive pregnancy (non-PRE) were genotyped for the CAG repeat length of the AR gene. Secondly, the ARCAG repeat lengths of 133 unrelated preeclamptic women and 112 healthy controls were studied. The mean AR gene CAG lengths were compared between the preeclampsia and the control groups.

RESULTS

The mean length of the CAG repeat segment among children was significantly shorter in the PRE group compared with the non-PRE group (p = 0.02). Interestingly, the difference between the PRE and the non-PRE boys was even more significant (p = 0.008). Also the distribution of allele frequencies was different, short repeat lengths being overrepresented in the PRE children. However, there were no significant differences in the mean CAG repeat lengths between the unrelated preeclamptic women and their controls, but the shortest CAG repeat lengths were found only in the preeclamptic women.

CONCLUSIONS

The AR gene CAG repeat length is not a major determinant in the development of preeclampsia. The association of the shortest CAG repeats with preeclampsia is possible, but a larger study group is needed to confirm this finding.

Tumour necrosis factor-alpha gene haplotype is associated with pre-eclampsia

We determined whether polymorphisms in the promoter region of the tumour necrosis factor alpha (TNF-alpha) gene contributes to differences in susceptibility to develop pre-eclampsia. The study involved 133 pre-eclamptic and 115 healthy pregnant women who were genotyped for the G-308A polymorphism of the TNF-alpha gene. The frequency of the G-308A allele was more common in the pre-eclampsia group than among the controls (P=0.046), giving an odds ratio of 0.57 (95% CI: 0.32-0.99), but there were no differences in the genotype distribution. The data from the G-308A polymorphism was combined with the previously published genotype and allele data from the C-850T polymorphism of the TNF-alpha gene, and used to assess a haplotype estimation analysis. Estimated overall pair of loci haplotype frequencies differed significantly between the groups (P=0.023+/-0.004). In the single haplotype association analysis, the haplotype C-A versus others was over-represented in the pre-eclampsia group (P=0.041+/-0.003), whereas the haplotype T-G versus others was less common in the pre-eclampsia group (P=0.035+/-0.003), compared with the controls. In conclusion, the polymorphisms of the TNF-alpha gene showed a significant haplotype association with susceptibility to pre-eclampsia in the Finnish population.

Changing incidence and outcome of infants with respiratory distress syndrome in the 1990s: a population-based survey

AIM

To evaluate the trends in the incidence, clinical course and outcome of respiratory distress syndrome (RDS) in the newborn in the Oulu University Hospital region in northern Finland.

METHODS

In the population of 58 990 infants, the incidence rates of RDS specific to gestational age and birthweight in two consecutive periods, 1990-95 and 1996-99, were calculated. Clinical course and other neonatal morbidities were reported. All surviving infants were followed up until 1 y of corrected age.

RESULTS

The overall incidence of RDS did not change significantly (8.7/1000 livebirths in 1990-95 vs 7.6 in 1996-99; p = 0.15), but the gestational age-adjusted incidence decreased between the two consecutive periods (p = 0.005). The frequency of infants with gestational age below 28 wk tended to increase towards the late 1990s, while their RDS incidence remained unchanged. RDS-related neonatal mortality decreased in parallel with neonatal mortality, accounting for 15% of all neonatal deaths. The duration of oxygen therapy shortened (8.0 vs 5.5 d) and the incidence of pneumothorax decreased (9.7 vs 4.1%), whereas the rate of chronic lung disease at 36 wk of postconceptional age (16.4 vs 16.7%) and at 1 y of corrected age (9.2 vs 8.2%) remained unchanged, as did also associated neurosensory morbidity (8.8 vs 9.5%).

CONCLUSION

During the 1990s, the incidence of RDS shifted towards more immature infants and the gestational-age specific incidence decreased. The course of the disease shortened and acute complications decreased. The frequency of chronic pulmonary sequelae (and associated neurosensory morbidity) at the age of 1 y did not change significantly.

Nitric oxide treatment and acute pulmonary inflammatory response in very premature infants with intractable respiratory failure shortly after birth

AIM

Premature infants with respiratory failure and early-onset pneumonia have low inducible nitric oxide synthase (NOS2) and no evidence of nitric oxide (NO) toxicity. However, inhalation of NO may not be indicated in sepsis because excessive NO generation has been reported. This prospective study was designed to test the hypothesis that inhaled NO is effective in a select group of small premature infants and that the responsiveness to NO is associated with low NOS2 enzyme.

METHODS

246 very low birthweight infants (birthweight <1500 g, VLBW) were screened for severe, intractable respiratory failure (oxygenation index >40, arterial-alveolar ratio for oxygen tension <0.10) that does not respond to two doses of surfactant within 5 h from birth. Infants with severe cardiac failure or a bleeding disorder were excluded. Five of the nine eligible cases received inhaled NO. They all had prolonged rupture of foetal membranes, early-onset pneumonia and persistent pulmonary hypertension.

RESULTS

All five responded strikingly, survived and appeared normal in follow-up. Airway specimens during the first day of life revealed very low NOS2, interleukin-1beta and surfactant protein A, compared with VLBW infants who had no acute infection despite histological chorioamnionitis. In early-onset pneumonia, NOS2 and other inflammatory mediators increased first during the recovery 1-2 d after birth.

CONCLUSION

VLBW infants with progressive respiratory failure and infection at birth have deficient pulmonary NOS2 and cytokine response. After surfactant therapy, these infants responded strikingly to inhaled NO. An acute pulmonary inflammatory response may contribute to respiratory adaptation in early-onset pneumonia.

Effects of short-term dexamethasone treatment on collagen synthesis and degradation markers in preterm infants with developing lung disease

AIM

To assess the effects of dexamethasone treatment on collagen turnover in preterm infants.

METHODS

The serum concentrations of the amino-terminal propeptide of type I and III procollagens (PINP and PIIINP), which reflect rates of type I and III collagen synthesis, respectively, and the carboxy-terminal telopeptide of type I procollagen (ICTP), which reflects the rate of type I collagen degradation, were monitored in 13 preterm infants receiving dexamethasone and 13 matched control infants without glucocorticoid treatment for a total period of 12 mo. Dexamethasone was started at a median age of 12 d and continued at tapering doses for a median total duration of 10 d. Blood samples were taken immediately after birth, at 7, 14 and 28 d of age and at 2, 3, 6, 9 and 12 mo. The same markers were also measured just before the initiation of dexamethasone and on days 1, 3, and 7 of treatment.

RESULTS

A striking decrease in all of the markers was already observed in every case on day 1 of dexamethasone, the suppression being greatest on day 3 and still considerable on day 7. The percentages from the pretreatment levels recorded on days 1, 3 and 7 were: for PINP 51, 26 and 45%; for PIIINP 63, 44% and 52%; and for ICTP 64, 41 and 51%. A rebound rise in PINP levels was seen in dexamethasone-treated infants, the levels exceeding those of the controls at 3 and 6 mo of age. A similar phenomenon was noted concerning PIIINP at 3 mo. The levels settled down at 9 and 12 mo.

CONCLUSION

Dexamethasone causes an immediate, inevitable, deep suppression of type I and III collagen synthesis and also type I collagen degradation. This should be taken into consideration, e.g. when assessing for the indications for steroid treatment in sick preterm infants and its dosing and duration.

Effect of short-term antenatal dexamethasone administration on type I collagen synthesis and degradation in preterm infants at birth

To assess the effects of antenatal corticoid administration on foetal collagen metabolism, cord serum concentrations of the aminoterminal propeptide and carboxyterminal telopeptide of type I procollagen (PINP and ICTP), which reflect rates of type I collagen synthesis and degradation, respectively, were measured in 67 consecutive preterm infants with gestational ages ranging from 24 to 32 wk. The samples were divided into three groups, depending on the administration and timing of antenatal corticosteroid treatment for enhancement of foetal lung maturity: cases in which the mothers had received a full 2-dose administration of dexamethasone on consecutive days 1 to 6 d before delivery (n = 23; Complete-Dexa), those who had received only a single dose of dexamethasone less than 24 h before delivery (n = 17; Partial-Dexa) and those who had not received any antenatal steroids (n = 27; No-Dexa). Infants in the Complete-Dexa group had significantly lower median PINP levels than those in the No-Dexa group (3,326 vs 4,028 microg/l; p = 0.036); the median PINP level in the Partial-Dexa group (3,999 microg/l) was close to that of the No-Dexa group. No significant differences in ICTP concentrations were seen between the groups.

CONCLUSION

A significant suppression of foetal collagen synthesis but not degradation was found to be associated with antenatal dexamethasone administration. This should be taken into consideration, e.g. when assessing whether to administer repeated or single courses of corticosteroids antenatally in high-risk pregnancies.

Type I collagen markers in cord serum of appropriate vs. small for gestational age infants born during the second half of pregnancy

BACKGROUND

The serum concentration of the N-terminal propeptide of type I procollagen (PINP) reflects the synthesis rate of type I collagen, whereas the corresponding C-terminal telopeptide (ICTP) mirrors its degradation.

DESIGN

PINP and ICTP were measured in a total of 690 cord serum samples from 592 appropriate-for-gestational-age (AGA) infants and 98 smal-for-gestational-age (SGA) infants. These markers were compared between AGA and SGA infants of different gestational ages, ranging from 23 to 41 weeks, and birth weights, from 620 to 4555 g.

RESULTS

Both PINP and ICTP levels were very high in the preterm AGA infants and declined significantly with advancing gestational age, paralleling the shape of the fetal growth velocity curve. Regardless of the quite large interindividual variations observed in these markers, PINP was significantly lower in both the preterm and term AGA infants than in the SGA infants. This was also the case for ICTP in the preterm infants of gestational age less than 36 weeks. In stepwise multiple regression analyses, gestational age, being either AGA or SGA and head circumference were significant factors to explain the levels of PINP and ICTP. The levels of PINP and ICTP were correlated with each other highly significantly in both the AGA and SGA infants (rs = 0.700 and 0.692, respectively; P < 0.001 in both).

CONCLUSIONS

The levels of type I collagen markers seem to follow closely the shape of the fetal growth velocity curve during different stages of gestation. However, because of the large interindividual variations observed, further studies are needed before the significance of these markers for the assessment of normal and abnormal fetal growth can be established.

Prematurity-associated nephrocalcinosis and kidney function in early childhood

To assess the impact of prematurity-associated nephrocalcinosis on kidney function later in life, 20 premature children with neonatal nephrocalcinosis and 20 controls, matched for birth weight and postnatal age but without nephrocalcinosis, were examined (birth weight 905+/-209 vs. 957+/-226 g; study age 4.7+/-1.1 vs. 4.6+/-0.9 years). Distal tubular acidification capacity was measured with the oral acetazolamide test, in which the response was abnormal in 1 out of the 20 children with a history of nephrocalcinosis, but in none of the controls. Urinary calcium and beta(2)-microglobulin excretion were higher in the children with nephrocalcinosis, but no differences were found in fractional excretion of sodium and potassium or tubular reabsorption of phosphate. Estimated creatinine clearance was not different between the groups. Of the 6 children with nephrocalcinosis lasting beyond 2 years of age, 5 had had chronic lung disease neonatally and exhibited a tendency for compensated respiratory acidosis at the time of the examination. Neonatal nephrocalcinosis seems to lead to some signs of renal tubular dysfunction in early childhood of preterm infants. Glomerular function, however, appears not to be specifically disturbed by nephrocalcinosis.

Nephrocalcinosis in full-term infants receiving furosemide treatment for congestive heart failure: a study of the incidence and 2-year follow up

In order to study the incidence and course of nephrocalcinosis in full-term infants with congestive heart failure receiving long-term furosemide treatment, 36 such infants (median age 2.9 months, range 1.2-8.0) and 36 full-term control infants not receiving any diuretics (median age 3.4 months, range 1.1-8.4) were studied by renal ultrasonography and random urine calcium variables. The infants with nephrocalcinosis were followed at 3-6 month intervals up to 2 years of age, or until ultrasonic resolution. Nephrocalcinosis was found in 5 out of the 36 (14%) treated infants, but in none of the controls (P = 0.03). The dose of furosemide was higher in the infants with nephrocalcinosis than in those without (1.9+/-0.6 vs. 1.3+/-0.4 mg/kg per day; P = 0.01). The urinary calcium concentration was higher in the infants receiving furosemide than in controls and a similar trend was observed in the urinary calcium/creatinine ratio, but these variables did not differ between the study infants with and without nephrocalcinosis. Ultrasonic resolution of nephrocalcinosis was observed in 3 of the 5 infants at 12 months, but in the other 2 the condition still persisted at 24 months.

CONCLUSIONS

Long-term furosemide treatment in full-term infants with congestive heart failure entails a considerable risk of developing nephrocalcinosis. Renal ultrasonography is warranted in these patients within a few months after initiation of the treatment and in the case of nephrocalcinosis alteration of the diuretic regimen is to be considered.

Incidence, ultrasonic patterns and resolution of nephrocalcinosis in very low birthweight infants

This longitudinal study was undertaken in order to elucidate the incidence and natural course of nephrocalcinosis in preterm infants and to evaluate whether the ultrasonic classification for nephrocalcinosis used here is suitable for predicting subsequent resolution of the condition. A total of 129 very low birthweight infants were screened for nephrocalcinosis by renal ultrasonography at 2 wk, 6 wk and 3 mo. The pyramidal changes were classified as peripheral, scattered or extensive. Follow-up renal ultrasonography was performed on the infants with nephrocalcinosis at 6, 12, 18 and 24 mo, and thereafter annually up to 6 y of age, or until ultrasonic resolution. The overall incidence of nephrocalcinosis was 20% (26/129). Nephrocalcinotic changes were peripheral in 14 out of the 26 infants (54%), scattered in 7 (27%) and extensive in 5 (19%). Ultrasonic resolution had taken place in all the cases with peripheral nephrocalcinosis by 12 mo, but 3 of the 7 infants with the scattered pattern and 3 of the 4 with the extensive pattern (1 died) were still affected at 24 mo. In two cases with extensive nephrocalcinosis the condition still persisted at 5-6 y of age. We conclude that about 20% of very low birthweight infants develop nephrocalcinosis during the first 3 mo of life. In about half of the affected infants renal changes are restricted and transient, but more extensive forms may last several years. The classification of nephrocalcinosis used here is appropriate for predicting later ultrasonic resolution.

Hypercalcemia and nephrocalcinosis in patients with congenital lactase deficiency

We describe 11 infants with congenital lactase deficiency, whose age at diagnosis varied from 6 to 88 days. At the time of admission, 7 of 10 infants had hypercalcemia. Five of the seven infants for whom renal ultrasonography was performed at the time of diagnosis had medullary nephrocalcinosis. Hypercalcemia ceased within a week of the start of a lactose-free diet. At the time of reevaluation, at the ages of 2 to 10 years, one of the patients still had hypercalciuria and nephrocalcinosis was still present in 3 of 11 patients. The mechanism of hypercalcemia is unclear but may be related to metabolic acidosis or may be promoted by the lactose effect (i.e., by nonhydrolyzed lactose that has a direct enhancing effect on calcium absorption in the ileum).