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Biomedical subjects

G L Nielsen

Publications and source records attributed to G L Nielsen.

At least 19 recordsLinked to original sources

Risk of specific congenital abnormalities in offspring of women with diabetes.

AIMS: To assess the extent to which the increased risk of congenital abnormalities seen in women with pre-gestational insulin-treated diabetes mellitus is unspecific or related to the embryology of specific organs. METHODS: Cases with congenital abnormalities were identified in the population-based Hungarian Congenital Abnormality Registry from 1980 to 1996 with two newborn children without congenital abnormality selected from the National Birth Registry as controls. We adjusted for parity, maternal age, and use of antipsychotic drugs. RESULTS: Among cases we found 63/22,843 babies with maternal diabetes compared with 50/38,151 in the control group [adjusted prevalence odds ratio (POR) 2.1; 95% CI 1.5-3.1]. The association was strongest for the following congenital abnormalities: renal agenesis (POR: 14.8; 95% CI, 3.5-62.1), obstructive congenital abnormalities of the urinary tract (POR: 4.3; 95% CI, 1.3-13.9), cardiovascular congenital abnormalities (POR: 3.4; 95% CI, 2.0-5.7), and multiple congenital abnormalities (POR: 5.0; 95% CI, 2.4-10.2). CONCLUSIONS: These data indicate that pre-gestational maternal diabetes is associated with strong teratogenic effects on the kidney, urinary tract, and heart, and strongly associated with multiple congenital abnormalities. We found no material association between diabetes and spinal congenital abnormalities and limb deficiencies.

Abnormalities, Drug-Induced↗

Pre-hospital parenteral antibiotic treatment of meningococcal disease and case fatality: a Danish population-based cohort study.

OBJECTIVES: Studies about the efficiency of pre-hospital antibiotic treatment of meningococcal disease are conflicting. We examined the case fatality rate in patients with meningococcal disease treated with pre-hospital antibiotics. METHODS: A cohort study of 534 patients hospitalized with meningococcal disease from two Danish counties. Clinical data were obtained from referral letters from general practitioners and hospital records. Complete follow-up for all patient until death or discharge. RESULTS: Seventy-seven patients (16% of the patients seen by a general practitioner) received parenteral antibiotics before hospital admission; 9 (12%) of them died. Of 402 patients who did not receive pre-hospital parenteral antibiotics, 26 (7%) died. The overall risk of case fatality among antibiotic-treated patients was increased with adjusted odds ratio (OR) = 2.4 (95% CI, 1.0-5.6). Meningococcus serogroup B was associated with increased case fatality in patients who received pre-hospital parenteral antibiotics (OR = 2.6; 95% CI, 0.8-8.3) in contrast to other serogroups. In Aarhus County there were no deaths in patients who received pre-hospital parenteral antibiotics, but in North Jutland County the case fatality was high (OR = 2.9; 95% CI, 1.2-6.8). CONCLUSIONS: The efficiency of pre-hospital parenteral antibiotic treatment seems to be dependent on hospital care and may vary with the serogroup.

Adolescent↗

Birth outcome of 1886 pregnancies after exposure to phenoxymethylpenicillin in utero.

OBJECTIVE: To examine the risk of congenital abnormalities, preterm birth and low birth weight after exposure to phenoxymethylpenicillin in utero. METHODS: A population-based follow-up study in the County of North Jutland, Denmark. Birth outcome for 1886 women, who redeemed prescriptions for phenoxymethylpenicillin during pregnancy was compared with the outcome for 9263 women who did not redeem any prescription during pregnancy. RESULTS: The prevalence of congenital abnormalities in 654 users of phenoxymethylpenicillin with or without other drugs during the first trimester was 4.6% compared with 3.6% in the reference group, giving a prevalence odds ratio of 1.25 (95% CI: 0.84-1.86). The prevalence odds ratio was 1.35 (95% CI: 0.59-3.08) in 131 women who were exposed to phenoxymethylpenicillin only. Nine cardiovascular abnormalities were found, giving an adjusted prevalence odds ratio of 1.74 (95% CI: 0.83-3.65). The prevalence odds ratios of preterm birth and low birth weight were 0.83 (95% CI: 0.66-1.04) and 1.02 (95% CI: 0.71-1.47), respectively. CONCLUSION: We found no significantly increased risk of congenital abnormalities, including cardiovascular abnormalities, preterm birth, or low birth weight in women who purchased phenoxymethylpenicillin during pregnancy.

Abnormalities, Drug-Induced↗

Angiotensin-converting enzyme inhibitors and the risk of cancer: a population-based cohort study in Denmark.

BACKGROUND: A recent observational study suggested that the use of angiotensin-converting enzyme (ACE) inhibitors protects against cancer in general and against breast and female reproductive tract cancers in particular. To explore these hypotheses, the authors examined cancer risk among users of ACE inhibitors in North Jutland County, Denmark. METHODS: Using data from the population-based Prescription Database of North Jutland County and the Danish Cancer Registry, cancer incidence among 17,897 individuals prescribed ACE inhibitors was compared with expected incidence based on county specific cancer rates during an 8-year study period with a mean follow-up of 3.7 years. Standardized incidence ratios (SIRs) with corresponding 95% confidence intervals (95% CIs) were calculated for cancers overall and at selected sites. In addition, the authors performed a direct comparison of users of ACE inhibitors with users of beta-blockers or calcium channel blockers (n = 47,579 individuals) by means of a Cox proportional hazards model. RESULTS: Overall, 909 cancer cases were observed among users of ACE inhibitors, with 846 expected based on general population rates, yielding an SIR of 1.07 (95% CI, 1.01-1.15). No risk reductions were observed for cancers of the breast and female reproductive tract, whereas nonsignificantly decreased SIRs were observed for cancers of the esophagus, stomach, and liver. Cancer of the kidney was found in significant excess (SIR, 1.6; 95% CI, 1.1-2.2). Stratification by duration of follow-up or number of prescriptions revealed no apparent trends, except for a tendency toward decreasing risk with increasing length of follow-up for smoking-related cancers. The direct comparison of users of ACE inhibitors with users of beta-blockers or calcium channel blockers yielded results comparable to those derived from the comparison with the general population, with a hazard ratio for cancer overall of 1.01 (95% CI, 0.93-1.09). CONCLUSIONS: This large, population-based cohort study did not confirm a protective effect of ACE inhibitors on the development of cancer. The excess of kidney cancer observed likely reflects a correlation between hypertension and kidney cancer. Further investigation is needed to evaluate the long-term effects of ACE inhibitors beyond the observation period of this and previous studies. Also, the suggestive evidence of decreased risks for upper digestive system cancers and for smoking-related cancers over time may warrant additional investigation.

Adult↗

Risk of adverse birth outcome and miscarriage in pregnant users of non-steroidal anti-inflammatory drugs: population based observational study and case-control study.

OBJECTIVE: To estimate the risk of adverse birth outcome in women who take non-steroidal anti-inflammatory drugs during pregnancy. DESIGN AND SETTING: Population based cohort study and a case-control study, both based on data from a prescription registry, the Danish birth registry, and one county's hospital discharge registry. PARTICIPANTS: COHORT STUDY: 1462 pregnant women who had taken up prescriptions for non-steroidal anti-inflammatory drugs in the period from 30 days before conception to birth and 17 259 pregnant women who were not prescribed any drugs during pregnancy. CASE-CONTROL STUDY: 4268 women who had miscarriages, of whom 63 had taken non-steroidal anti-inflammatory drugs, and 29 750 primiparous controls who had live births. MAIN OUTCOME MEASURES: Incidences of congenital abnormality, low birth weight, preterm birth, and miscarriage. RESULTS: Odds ratios for congenital abnormality, low birth weight, and preterm birth among women who took up prescriptions for non-steroidal anti-inflammatory drugs were 1.27 (95% confidence interval 0.93 to 1.75), 0.79 (0.45 to 1.38), and 1.05 (0.80 to 1.39) respectively. Odds ratios for the taking up of prescriptions in the weeks before miscarriage ranged from 6.99 (2.75 to 17.74) when prescriptions were taken up during the last week before the miscarriage to 2.69 (1.81 to 4.00) when taken up between 7 and 9 weeks before. The risk estimates were no different when the analysis was restricted to missed abortions. CONCLUSIONS: Use of non-steroidal anti-inflammatory drugs during pregnancy does not seem to increase the risk of adverse birth outcome but is associated with increased risk of miscarriage.

Abnormalities, Drug-Induced↗

Risk of hospitalization resulting from upper gastrointestinal bleeding among patients taking corticosteroids: a register-based cohort study.

PURPOSE: We assessed the risk of hospitalization for upper gastrointestinal bleeding among patients using systemic corticosteroids, accounting for the use of other drugs that may increase the risk of bleeding. SUBJECTS AND METHODS: We conducted a population-based cohort study in North Jutland County, Denmark. Data on the use of corticosteroids, nonsteroidal anti-inflammatory drugs, aspirin, and anticoagulants during 1991 to 1995 were obtained from a countywide prescription database. All hospitalizations because of upper gastrointestinal bleeding were identified through the Hospital Discharge Registry. The observed numbers of patients with gastrointestinal bleeding in various exposure categories among corticosteroid users were compared with the expected number based on the North Jutland population who did not receive prescriptions for any of the drugs under study. RESULTS: A total of 45,980 patients accrued 18,379 person-years of corticosteroid use. There were 109 hospital admissions for gastrointestinal bleeding among corticosteroid users, compared with 26 expected, yielding a relative risk of 4.2 [95% confidence interval (CI): 3.4 to 5.0]. Among corticosteroid users who did not use other drugs associated with gastrointestinal bleeding, the relative risk was 2.9 (95% CI: 2.2 to 3.7). The relative risk decreased further to 1.9 (95% CI: 1.4 to 2.5) when current corticosteroid usage was compared with former usage. CONCLUSION: We observed an increased risk of hospitalization because of upper gastrointestinal bleeding among patients prescribed corticosteroids, especially among those who use other medications. Confounding from the underlying disease may also have contributed to the observed increase in risk.

Adolescent↗

Birth outcome following maternal use of fluoroquinolones.

The aim of the study was to examine fetal risk associated with intrauterine exposure to fluoroquinolones. By using on record linkage between a Prescription Database and the Birth Registry in Denmark, the offspring of 57 users of fluoroquinolones and of 17259 patients who had no prescriptive medication during pregnancy, were compared in a cohort study. Among the users, the prevalence rate ratios of congenital abnormalities, preterm birth and low birth weight were 1.30 (95% CI: 0.30-5.30),1.53 (95% CI: 0.62-3.80) and 1.17 (95% CI: 0.15-8.90), respectively. The risk of congenital abnormalities among users of fluoroquinolones during pregnancy was close to unity. Despite these limitations of statistical analysis the study suggested that the use of fluoroquinolones during pregnancy may not be a major risk factor to the foetus.

Abnormalities, Drug-Induced↗

Induced abortion and placenta complications in the subsequent pregnancy.

BACKGROUND: To study the risk of placenta complications following an induced abortion as a function of the interpregnancy interval. METHODS: This study is based on three Danish national registries; the Medical Birth Registry, the Hospital Discharge Registry, and the Induced Abortion Registry. All primigravida women from 1980 to 1982 were identified in these three registries. A total of 15,727 women who terminated the pregnancy with a first trimester induced abortion were selected to the abortion cohort, and 46,026 women who did not terminate the pregnancy with an induced abortion constituted the control cohort. By register linkage all subsequent pregnancies were identified from 1980 to 1994. Only women who had a non-terminated pregnancy following the index pregnancy were selected to the study. Placenta complications were identified using either the Hospital Discharge Registry ICD-8 codes or the Medical Birth Registry records. RESULTS: A slightly higher risk of placenta complications following an abortion was found. Retained placenta occurred more frequently in women with one, two or more previous abortions, compared with women without any previous abortion of similar gravidity. Adjusting for maternal age and residence at time of pregnancy, the interpregnancy interval, and the number of previous miscarriages (control cohort only), the odds ratios of retained placenta in deliveries of singleton live births in women with one previous abortion was 1.17 (95%CI=1.02-1.35), and for women with two or more previous abortions it was 1.68 (95%CI=1.23-2.30), respectively, compared with the control cohort of similar gravidity. Only for women who had one abortion did the results follow the predicted pattern of a higher risk of retained placenta after a short pregnancy interval. No association with placenta previa was seen. CONCLUSIONS: The findings suggest a positive association between abortions and retained placenta in subsequent singleton live births, but the association was weak and confounding cannot be ruled out.

Abortion, Induced↗

Birth outcome and risk of neonatal hypoglycaemia following in utero exposure to pivmecillinam: a population-based cohort study with 414 exposed pregnancies.

Concerns have been raised as to the safety of using pivaloyl-conjugated beta-lactam antibiotics during pregnancy as they cause carnitine depletion. Restrictions have been recommended in some Scandinavian countries as drug-induced carnitine depletion could constitute a risk to the developing foetus. One of these drugs, pivmecillinam, is widely used against urinary tract infections but few data exist concerning its safety in pregnancy. In a cohort study, we compared the prevalences of congenital abnormalities, pre-term delivery, low birth weight, low Apgar score and neonatal hypoglycaemia in the offspring of 414 women who had at least 1 prescription for pivmecillinam redeemed during pregnancy with those of the offspring of 7472 pregnant women for whom no drugs were prescribed during pregnancy. The prevalence of congenital abnormalities was 1.7% among 119 infants exposed in the first trimester and 3.7% among the reference group [odds ratio (OR) 0.46; 95% confidence interval (CI) 0.11-1.86]. We found no significantly increased risks in either pre-term delivery (OR 0.91, 95% CI 0.11-1.86), low birth weight (OR 0.57, 95%, CI 0.23-1.41), low Apgar score (OR 2.32, 95% CI 0.30-18.16) or hypoglycaemia (OR 0.73, 95% CI 0.18-3.00) that were induced by carnitine depletion. No significantly increased risk in adverse birth outcome was therefore found in women treated with pivmecillinam.

Abnormalities, Drug-Induced↗

Do pregnant women report use of dispensed medications?

Surveillance of drug safety in pregnancy often draws on administrative prescription registries. Noncompliance in the use of prescribed medication may be frequent among pregnant women owing to their fear of fetotoxic side effects. To estimate compliance in the use of prescription drugs dispensed during pregnancy, we compared prescription data from the North Jutland Prescription Database with information on drug use provided by pregnant women to the Danish National Birth Cohort (DNBC), which is a health interview survey. We used the North Jutland Prescription Database to identify all prescription drugs dispensed during pregnancy for the 2,041 women who were enrolled in the DNBC in the County of North Jutland, Denmark. Compliance was defined as the probability of reporting drug use in DNBC after purchasing a dispensed prescription drug. The overall compliance to drugs purchased within 120 days before the interview was 43% (95% confidence interval = 40-46). Drugs used for treating chronic diseases, for example, beta-blockers, insulin, thyroid hormones, and diuretic and antiepileptic drugs, were always reported to be used, but compliance was low for drugs used for local or short-term treatment such as antihistamines, antibiotics, antacids, nonsteroid anti-inflammatory drugs, and gynecologic drugs. Thus, for the latter drug groups the prescription database may provide an incomplete identification of exposure. Neither data source is unbiased regarding actual drug intake. Nevertheless, our results indicate that for some drug groups risk assessment studies based on prescription data may produce false negative results as a result of noncompliance.

Cohort Studies↗

A population-based prescription study of asthma drugs during pregnancy: changing the intensity of asthma therapy and perinatal outcomes.

BACKGROUND: Among the goals of gestational asthma, therapy is optimisation of pulmonary function. According to the US Food and Drug Administration, no asthma drugs can be considered 'safe' during pregnancy. Fear of adverse fetal effects may thus lead to restrictive use of asthma drugs during pregnancy, and no population-based studies concerning gestational asthma therapy exist. OBJECTIVES: To examine whether asthma drugs or changing intensity of asthma therapy during pregnancy was associated with deviations from expected values of gestational age, birth weight, length at birth, or malformations. METHODS: The Birth Registry was used to identify all 15,756 primiparous women who gave birth in the County of North Jutland between 1991 and 1996. According to the North Jutland Prescription Database, 303 of these women received prescriptions for asthma drugs during pregnancy. Women who did not purchase any prescription drugs during pregnancy constituted the reference group. CONCLUSION: Women who received prescriptions for asthma drugs during pregnancy gave birth to infants with birth weight and length at birth within the expected limits. Reducing intensity of asthma treatment during pregnancy was associated with lower birth weight and length at birth. This may indicate that pregnant women chose to discontinue therapy although their disease severity justifies continuation of treatment. However, analyses did not take into account important clinical variables, and results could also be due to confounding factors or chance.

Adult↗

Hospitalisation for upper gastrointestinal bleeding associated with use of oral anticoagulants.

The incidence of hospitalisation for upper GI bleeding with use of oral anticoagulants (OA) alone or in combination with other drugs was examined in a cohort of 4,204 users of OA, identified through record linkage between a population-based prescription database and a hospital discharge registry in Denmark, and compared with the incidence in the general population not exposed to OA. The standardised incidence ratio (SIR) was 2.8 (95% CI = 1.6-4.5) for use of OA alone. SIRs tended to be higher for use of OA combined with acetaminophen alone (4.4, 95% CI = 1.2-11.4), non-aspirin NSAIDs alone (8.0, 95% CI = 2.1 to 20.4) or aspirin/corticosteroids alone (3.8, 95% CI = 0.8-11.0), respectively. These results indicate that use of OA is associated with a significantly increased risk of upper GI bleeding, with still higher risks associated with the concomitant use of other medications including acetaminophen. Further research is needed to clarify the extent to which drugs interacting with oral anticoagulants may cause GI bleeding and the mechanisms through which these associations operate.

Acetaminophen↗

[Antibiotic pre-hospital treatment and the course of meningococcal disease].

The aim of the study was to assess the effect of pre-hospital antibiotic treatment given by general practitioners to patients with meningococcal disease. It was carried out as a 16-year population-based historical follow-up study based on referral letters and hospital records in the County of North Jutland, Denmark, and included 320 patients with meningococcal disease, of whom 302 were examined by a general practitioner before admission to hospital. The main outcome measure was death. We found that 44 patients (14.6%) were given antibiotic treatment by the referring general practitioner. Nine of these (20.5%) died, compared with 16 (6.2%) patients who did not receive pre-hospital antibiotic treatment. The presence of skin bleeding, petechiae and impaired consciousness were strongly associated with case fatality. Even after adjustment for these variables the odds ratio for death in patients treated with antibiotics was high (3.2; 95% CI 0.9-10.6). In the 15 patients with skin bleeding (ecchymoses, suggillations) the case fatality rate was 100% in patients treated with antibiotics, and 50% in patients who did not receive antibiotics before hospitalization. It is concluded that pre-hospital treatment is mainly given to the most severe cases with expected high case fatality, and this confounding by indication was probably not fully adjusted for with the available data. The results contradict previous findings and provide reason to doubt the benefit of pre-hospital antibiotic treatment in patients with meningococcal disease.

Adolescent↗

[Incidence of cancer after primary deep venous thrombosis or pulmonary embolism].

We report a nationwide study based on a cohort of patients with a thromboembolic event (TE) defined as deep venous thrombosis and/or pulmonary embolism identified from the Danish National Registry of Patients from 1977 to 1993. Cancer occurrence in the cohort was determined by linkage to the Danish Cancer Registry. Expected number of cancer cases was estimated from age, sex and site-specific incidence rates. A total of 26,653 TE-cases were identified. We observed 1737 cases of cancer versus 1371 expected (SIR 1.3; 95% CI, 1.21 to 1.33). The risk was particularly high during the first months of follow-up, but declined rapidly hereafter to a constant level slightly above 1.0 one year after the TE. Forty percent of patients diagnosed with cancer within one year from the hospitalization for TE had distant metastases at the time of cancer diagnosis. The observed risk pattern provides evidence that most often a preclinical cancer gives rise to a subsequent TE. An aggressive search for hidden cancer in patients with TE is not warranted.

Adult↗

A population-based cohort study of birth and neonatal outcome in older primipara.

OBJECTIVES: To examine the risk of adverse birth outcome in older primiparous women. METHODS: We identified 14,676 primiparae of 20 years of age or more from 1991 to 1996 using the Birth Registry in the North Jutland County, Denmark. We evaluated the risk of adverse birth outcome in the primiparous women aged 30-34 years and above 35 years using the primiparae aged 20-29 years at time of birth as reference. RESULTS: The risks of induced labor, perineotomy, stimulating contraction and vacuum extraction were significantly higher (adjusted odds ratio: 1.3 to 1.7) in the primiparae of 35 years or more. The odds ratio for cesarean section delivery was 2.1 (95% confidence interval: 1.7-2.6) and the odds ratio for delivering a low birth weight child among the primiparae of 35 years or more was 2.2 (95% confidence interval: 1.4-3.3) compared with the primiparae of 20-29 years of age. These risk estimates were independent of women's infertility treatment history. CONCLUSIONS: A negative effect of maternal age on birth and neonatal outcome may be seen even after 30 years of age and is partly related to chronic diseases. However, it is impossible to rule out selection bias, but the actual risk must be taken into consideration in antenatal care.

Adult↗

Birth outcome following maternal use of metoclopramide. The Euromap study group.

AIMS: Metoclopramide is an antiemetic drug used widely during pregnancy for nausea and vomiting. Because of its frequent use any adverse effects on infant health would have major public health implications. We therefore examined the safety of metoclopramide during pregnancy. METHODS: Using the Pharmaco-Epidemiological Prescription Database of North Jutland County, we identified 309 women with singleton pregnancies who had prescriptions for metoclopramide fom 1 January 1991 to 31 December 1996. Information on malformations, birth weight, preterm deliveries and stillbirth were compared with 13 327 references who did not receive prescriptions of any kind during pregnancy. RESULTS: Mean birth weight among exposed women was 3480 g compared with 3470 g among nonexposed. Based on logistic regression models no major differences in the risk were found concerning malformations (OR= 1.11; 95% confidence interval (CI): 0.6-2.1); low birth weight (OR= 1.79; 95% CI: 0.8-3.9) or preterm delivery (OR= 1.02; 95 CI: 0.6-1.7). CONCLUSIONS: We could not document any association between the use of metoclopramide during pregnancy and adverse pregnancy outcome. Because of the limited power of our study further research is required.

Adolescent↗

Pregnancy outcome following prescription for sumatriptan.

BACKGROUND: Some 2.5% of fertile Danish women use sumatriptan, and the drug is also taken during pregnancy. Although sumatriptan reacts selectively in brain vessels, the possibility of reactions with placental blood flow and uterotonic activity cannot be ruled out. The aim of our study was to examine the association between sumatriptan exposure during pregnancy and the risk of preterm delivery and low birth weight. METHODS: Data from the Pharmaco-Epidemiological Prescription Database of North Jutland county regarding all women who had given birth in the county of North Jutland from 1991 to 1996 were linked to the Danish Medical Birth Registry. Women who were exposed to sumatriptan during pregnancy were identified (n = 34), and using logistic regression models their pregnancy outcome was compared with two groups of pregnant women: (1) healthy women (n = 15 955) and (2) migraine controls (n = 89), defined as migraine patients who did not redeem prescriptions for migraine treatment during pregnancy. RESULTS: The risk of preterm delivery was elevated among women exposed to sumatriptan compared with migraine controls (odds ratio [OR] 6.3, 95% confidence interval [CI] 1.2-32.0) and healthy women (OR 3.3, 95% CI 1.3-8.5). The odds ratio for having a newborn with a low birth weight was increased (OR 3.0, 95% CI 1.3-7.0) for all migraine patients who delivered at term (n=115) compared with the outcome of healthy pregnancies. CONCLUSIONS: We found that sumatriptan exposure during pregnancy was associated with an increased risk of preterm delivery and low birth weight. These findings may be due to drug exposure, but they may also reflect the impact of disease severity rather than the treatment itself, or confounding, or chance.

Adult↗