[Christmas article. Significantly fewer acute hospital admissions on days off]

The number of acute admissions in Danish hospitals is increasing and is causing recurrent overcrowding problems. There are fewer hospitalisations on days off, like weekends, public holidays and vacations, and this phenomenon is analysed in our review with data from the period 1.1.2008-31.12.2017. There were 20-30% fewer acute admissions on days off than on the about 60% normal working days in Denmark, and apparently without compensatory increases following the days off. Our findings suggest, that 1) doctors' indications for acute admissions cannot possibly be based on strict clinical criteria alone, and 2) the problem of growing hospitalisation and overcrowding could perhaps be attenuated by increasing the number of days off in the Danish healthcare system. However, further studies are required, to ensure that the quality of patient care is not adversely affected.

[Medication reconciliation]

The purpose of medicines reconciliation (MR) is to avoid medication errors through the complete and accurate transfer of information on patients' medicines during health care sector transitions. We review the rapidly expanding literature on MR showing a need for consensus on taxonomy and research into efficient ways to implement MR. Further, we describe quality improvement initiatives on MR in Denmark and challenge the, in our view, one-sided focus on information technology in MR.

Occurrence of Anaemia in the First Year of Inflammatory Bowel Disease in a European Population-based Inception Cohort-An ECCO-EpiCom Study

BACKGROUND AND AIMS

Anaemia is an important complication of inflammatory bowel disease [IBD]. The aim of this study was to determine the prevalence of anaemia and the practice of anaemia screening during the first year following diagnosis, in a European prospective population-based inception cohort.

METHODS

Newly diagnosed IBD patients were included and followed prospectively for 1 year in 29 European and one Australian centre. Clinical data including demographics, medical therapy, surgery and blood samples were collected. Anaemia was defined according to the World Health Organization criteria.

RESULTS

A total of 1871 patients (Crohn's disease [CD]: 686, 88%; ulcerative colitis [UC]: 1,021, 87%; IBD unclassified [IBDU] 164. 81%) were included in the study. The prevalence of anaemia was higher in CD than in UC patients and, overall, 49% of CD and 39% of UC patients experienced at least one instance of anaemia during the first 12 months after diagnosis. UC patients with more extensive disease and those from Eastern European countries, and CD patients with penetrating disease or colonic disease location, had higher risks of anaemia. CD and UC patients in need of none or only mild anti-inflammatory treatment had a lower risk of anaemia. In a significant proportion of patients, anaemia was not assessed until several months after diagnosis, and in almost half of all cases of anaemia a thorough work-up was not performed.

CONCLUSIONS

Overall, 42% of patients had at least one instance of anaemia during the first year following diagnosis. Most patients were assessed for anaemia regularly; however, a full anaemia work-up was frequently neglected in this community setting.

Text mining electronic health records to identify hospital adverse events

Manual reviews of health records to identify possible adverse events are time consuming. We are developing a method based on natural language processing to quickly search electronic health records for common triggers and adverse events. Our results agree fairly well with those obtained using manual reviews, and we therefore believe that it is possible to develop automatic tools for monitoring aspects of patient safety.

[Patient deaths are not suited for monitoring quality and patient safety in hospitals]

Although some patient deaths in hospitals can be prevented if quality of care and patient safety are improved, it is not given that such deaths can be used to track improvements. Since preventable deaths only amount to about 5% of all deaths, a decline in that number will be a weak signal as far as mortality is concerned. The commonly used hospital standardised mortality ratio (HSMR) has a low signal-to-noise ratio and is therefore not suitable for monitoring. The same goes for structured reviews of health-care records of deceased patients. Consequently, a need to develop alternatives exists.

[Hospital standardised mortality ratios do not with certainty reflect the quality of patient care]

Hospital standardised mortality ratios (HSMRs) are presumed to reflect an overall quality of patient care in hospitals. Figures for all Danish hospitals are being published quarterly on the Internet, and aggregated values are used to set goals for both regional and nationwide efforts to improve quality of care and patient safety. We have analysed the available data from 2007 through 2011 and cannot reconcile the quite substantial and often sudden changes in HSMRs with changes in quality of care, but believe that they are due to inherent noise in calculating HSMRs, e.g. owing to variable quality of the diagnostic coding.

Meta-analysis on anxiety and depression in adult celiac disease

OBJECTIVE

We used meta-analysis to test hypotheses concerning whether adult celiac disease is reliably linked with anxiety and/or depression.

METHOD

We examined published reports on anxiety and depression in adult celiac disease.

RESULTS

Eighteen studies on depression and eleven studies on anxiety in adult celiac disease met selection criteria. They show that depression is reliably more common and/or more severe in adults with celiac disease than in healthy adults (overall meta-analysis effect size: 0.97). The fail-safe margin of unpublished reports that would be required to negate the finding exceeds 8000. Adults with celiac disease do not, however, differ reliably in terms of depression from adults with other physical illnesses, nor do they differ reliably from healthy adults or adults with other physical illnesses in terms of anxiety.

CONCLUSION

Depression is common in adult celiac disease and resembles the condition in other physical illnesses. We view the findings as support for the notion that non-specific mechanisms mediate emotional disorders in adult celiac disease.

First-time urea breath tests performed at home by 36,629 patients: a study of Helicobacter pylori prevalence in primary care

BACKGROUND

The aim of the current study was (1) to describe the use of a (13) C-urea breath test (UBT) that was performed by patients at their homes as a part of a test-and-treat strategy in primary care and (2) to investigate the prevalence of Helicobacter pylori in patients taking a first-time UBT.

MATERIAL AND METHODS

The patients performed UBTs at home based on the discretion of the general practitioner and mailed the breath bags to a central laboratory for analysis. Each patient was identified by a unique civil registration number. The study was population-based, and the background population was approximately 700,000 people.

RESULTS

From 2003 to 2009, 44,487 UBTs were performed. Of these, 36,629 were first-time UBTs. In total, 726 of 45,213 breath bags received (1.6%) were unable to be analyzed because of errors with the bags. For both women and men who were ≤ 45 years of age, positive H. pylori declined over the time course of the study (women: 19.6% in 2003 to 17.6% in 2009, p < .01; men: 20.7% in 2003 to 16.9% in 2009, p < .001). Patients who were older than 45 years had significantly higher positive H. pylori results than younger patients.

CONCLUSIONS

A test-and-treat system was possible to implement that allowed patients to perform UBTs at their homes. The results of the first-time UBTs demonstrated that approximately one of five patients who presented with dyspepsia in the clinical setting of Danish primary care was infected with H. pylori.

The long-term effect of alprenolol on plasma apolipoproteins A-I and B

The concentration of lipids, lipoproteins and apolipoprotein A-I and B was measured in the plasma of 33 patients, enrolled in a double-blind, controlled trial of alprenolol in myocardial infarction, after one year on the study medication and again after 6 months off the medication. Sixteen patients received 200 mg alprenolol twice daily and 17 received placebo. There were no statistically significant differences between the parameters in the two groups after one year on medication. However, when medication was stopped, the ratio of apolipoprotein B to apolipoprotein A-I fell by 9% in the alprenolol group and increased by 2% in the placebo group. This difference was statistically significant. Our results suggest that alprenolol, a beta-blocker with weak intrinsic sympathomimetic effect, has slight effects on plasma lipoproteins. These effects were apparent only by measurements of apolipoproteins.

[Uniform reference intervals and harmonised results in clinical biochemistry in Scandinavia--light ahead]

Danish laboratories are introducing identical reference intervals for a number of biochemical components in accordance with a Nordic agreement and recommendations during 2007. Danish doctors will consequently experience both changes in reference interval limits as well as adjustments of patients' levels of reported results for some components.

The common polymorphism of apolipoprotein E: geographical aspects and new pathophysiological relations

Apolipoprotein E (apoE) has important functions in systemic and local lipid transport, but also has other functions. The gene (APOE) shows a common polymorphism with three alleles--APOE*2, APOE*3, and APOE*4. Their frequencies vary substantially around the world, but APOE*3 is the most common almost everywhere and is often considered to be the ancestral or "wild-type" allele for that reason. However, there are several arguments for APOE*4 being the ancestral allele. But then, why has APOE*3 become so frequent? And why has APOE*4 not become extinct? The proportion of APOE*4 carriers increases from only 10-15% in southern Europe to 40-50% in the north. The gradient may be a trace of the demic expansion of agriculture that began about 10,000 years ago, but it may also reflect the possibility that APOE*4 carriers are less likely to develop vitamin D deficiency. The common APOE polymorphism is associated with varying risk of cardiovascular disease and Alzheimer's disease, but other interesting aspects may emerge in the future.

Trends in incidence, case-fatality and recurrence of myocardial infarction in the Danish MONICA population 1982-1991

BACKGROUND

Growing awareness of risk factors for myocardial infarction (MI), continuous mass campaigns on lifestyle factors, increasing use of heart rehabilitation and improved treatment should imply decreases in the incidence, case-fatality and recurrence rates of MI. The purpose of the study was to assess trends in the incidence, case-fatality and recurrence rate of MI and to analyse whether any changes seen were due to a period or a cohort effect.

METHODS

The Danish MONICA population comprises all men and women aged 25-74 years in the period 1982-1991 living in a suburban area of Copenhagen, Denmark. Fatal and non-fatal attacks classified as definite MI and non-fatal attacks classified as possible MI were included. The incidence rate was analysed by Poisson regression, the case-fatality rate by logistic regression, and the rate of recurrence by Cox regression. Age-period-cohort analyses were carried out according to a method described by Clayton and Schifflers.

RESULTS

During the 10-year period a significant decrease in the incidence rate of MI was seen for men and women and for the rate of recurrent MI. The decrease in incidence and recurrence could not unambiguously be ascribed to a period or cohort effect. The rate of case-fatality after a first MI was not changed significantly during the period, whereas men and women had different trends in case-fatality after recurrent MI.

CONCLUSIONS

In accordance with results from other Western countries we found a decline in the incidence and recurrence rate of MI. Contrary, the lack of a decrease in the case-fatality rate after a first MI was unexpected and difficult to explain.

Twelve single nucleotide polymorphisms on chromosome 19q13.2-13.3: linkage disequilibria and associations with basal cell carcinoma in Danish psoriatic patients

The genetic susceptibility to basal cell carcinoma (BCC) among Danish psoriatic patients was investigated in association studies with 12 single nucleotide polymorphisms on chromosome 19q13.2-3. The results show a significant association between BCC and the A-allele of a polymorphism in ERCCI exon4 (Odds ratio 12;95% Confidence Interval 1.17-124; p(chi2, two-side) = 0.019) and to a lesser extent with XPD exon6 (p = 0.06). This is in accordance with recent studies of a different group of BCC cases (Rockenbauer et al. (in press) Carcinogenesis; Yin et al. (manuscript submitted for publication). Cancer Epidemiol. Biomarkers Prev), which places two highly influential markers between these two genes. The analysis also confirmed that considerable linkage disequilibrium exists between SNPs both within genes and between genes in this region. The combined studies suggest that genetic variation in nucleotide excision repair is of importance for the development of BCC.

Differential expansion rates of small abdominal aortic aneurysms between the apolipoprotein E genotypes

Background

Carriers of the E4 allele for the gene encoding apolipoprotein E (apoE) have an increased risk of atherosclerosis. The distribution of apoE genotypes among men with a small abdominal aortic aneurysm (AAA) was compared with that among healthy men, and any differences between the genotypes in aneurysm expansion measured over 2–4·5 years were examined.

Methods

The patients originate from a population ultrasonographic screening programme with about 4800 participating 65–73-year-old men in a defined geographical region. Of 191 patients diagnosed, 57 of 77 who have been followed for 2 years or more were genotyped. Aneurysm expansion rates were determined from linear regression of diameter versus time of examination. The influence of apoE genotype on expansion rate was analysed using analysis of variance, with initial aneurysm size and smoking status as covariates.

Results

The E4E4 genotype was not seen among patients with an AAA, whereas three patients had the rare E2E4 genotype. These patients had higher expansion rates than patients with the common genotype E3E3 (P = 0·009), whereas patients with the genotype E3E4 had lower rates (P = 0·034) (see Table over).

Conclusion

The findings suggest that the common polymorphism of the apoE gene influences the prognosis in patients with a small AAA. As regards the E3E4 genotype, the findings are unexpected, when compared with the known influence of E4 on the risk of atherosclerosis. This may partly explain the familial tendency of AAA, and inconsistent finding of coexisting atherosclerosis in patients with AAA. However, an impact of selection bias, due to differential survival or referral to surgery of patients with AAA, cannot be excluded.

Trends in lifestyle coronary risk factors in the Danish MONICA population 1982-1992

Myocardial infarction incidence rate declined 3-5% per year during 1982-1992 in the Danish study population of the WHO MONICA Project. We examined whether smoking habits, alcohol intake, dietary habits and physical activity levels changed in the population during the same period. Data from 6695 men and women of ages 30, 40, 50 and 60 y, examined in 1982-4, in 1986-7, and in 1991-2, were analysed to estimate trends. A summary healthy eating index and six scores derived by factor analysis were used to analyse food frequency data. The percentage of smokers declined 1.6% per year in men, and 1.0% per year in 30-, 40- and 50-y-old women, but increased 0.9% per year in 60-y-old women. The percentages of heavy cigarette smoking men and women nevertheless remained constant and close to 30%. Total alcohol intake declined among 30-y-olds, but appeared constant in other age groups. However, among 60-y-old men and among women over 30, the percentage of wine-drinkers rose from 6-11% in 1982-4 to 9-18% in 1991-2. Only 60-y-old men became more physically active at work and only 30-y-old women more so in leisure times. The percentage of individuals with a low healthy eating index decreased and the percentage with a high index increased. More importantly, dietary factor scores showed trends suggesting that very profound and potentially beneficial changes in dietary habits occurred. Lifestyle in the DAN-MONICA population changed in several ways that may have contributed to the declining incidence of myocardial infarction during the 1980s.

Survival and cause of death after myocardial infarction: the Danish MONICA study

As part of the Danish WHO MONICA study, a register of patients with myocardial infarction was established in 1982, covering 11 municipalities in the western part of Copenhagen County, Denmark. During the period 1982-91, all cases of myocardial infarction among citizens aged 25-74 years were registered and validated according to the criteria set up for the WHO MONICA project. Short-term (28 days) and long-term (up to 15 years) survival in three periods were compared. The rate of mortality after a non-fatal myocardial infarction was compared with that of the general population, and causes of death were analyzed. Short-term survival did not change during the study period, whereas long-term survival improved for men but did not change for women. The excess mortality rate among female patients over that of the general population was due to ischemic heart disease, other cardiovascular diseases, cancer and other diseases. The excess mortality among male patients was due only to cardiovascular diseases.

[Trends in selected biological risk factors of cardiovascular diseases in the Danish MONICA population 1982-1992]

INTRODUCTION

The incidence rate of a first myocardial infarction declined 3-5% annually in the Danish WHO MONICA population in the period from 1982 to 1991. The aim of this study was to investigate whether levels of the most commonly considered biological traits associated with cardiovascular risk have changed in the Danish MONICA population during this period.

METHOD

Data from 6,695 men and women of 30, 40, 50 and 60 years of age, examined in the Danish WHO MONICA surveys in 1982-1984, 1986-1987, and 1991-1992, were analysed to estimate temporal trends in body height and weight, blood pressure, and serum total, HDL, and LDL cholesterol, and triglyceride.

RESULTS

Body height increased by 0.1% per year and the body mass index by 0.4% per year in women. The diastolic blood pressure increased 0.4% per year in women and 0.6% per year in 60-year-old men. HDL cholesterol declined 0.4% per year. Body mass indices in men, diastolic blood pressures in men < 60 years of age, systolic blood pressures, total and LDL cholesterol and triglyceride did not change.

DISCUSSION

The levels of biological risk factors in the Danish WHO MONICA study population did not show trends during the 1980s that contribute to explain the declining incidence of myocardial infarction in the population.

Regional and hormone-dependent effects of apolipoprotein E genotype on changes in bone mineral in perimenopausal women

We studied 479 perimenopausal Danish women aged 45-58 years to examine differences between APOE genotypes with respect to (1) baseline total body bone mineral density (BMD) and densities measured in five different regions (ultradistal forearm, proximal forearm, lumbar spine, femoral neck, and total hip region); (2) serum levels of alkaline phosphatase, bone isoenzyme alkaline phosphatase, osteocalcin, parathyroid hormone (PTH), 25-hydroxyvitamin D, and urine hydroxyproline/creatinine excretion ratio; and (3) changes in bone mineral during 5 years of follow-up. Baseline BMDs were identical, whereas serum levels of alkaline phosphatase and its bone isoenzyme were higher in women with APOE 2-2 and APOE 2-3 than in women with APOE 3-3 and APOE 3-4 and lower in women with APOE 4-4. Among women not receiving hormonal-replacement therapy (HRT; n = 262), those with APOE 2-2 and APOE 2-3 had 30-40% lower rates of femoral neck and total hip bone mineral loss than women with APOE 3-3 and APOE 3-4, whereas the rates of mineral loss in other skeletal regions did not differ between these APOE genotypes. Women with APOE 4-4 appeared to have lower rates of bone mineral loss in all regions. Women treated with hormones throughout the follow-up period (n = 113) gained bone mineral, and women with APOE 3-4 and APOE 4-4 gained relatively more mineral than other women. A comparison of untreated and treated women with APOE 2-3, APOE 3-3, and APOE 3-4 suggests a possible modification of the effect of APOE genotype by HRT. In conclusion, the common APOE polymorphism has a complex effect on bone metabolism in perimenopausal Danish women including possible modification by hormone use: (1) among women not receiving HRT, those with APOE*2 have lower bone mineral losses in the femoral neck and hip region than other women, and (2) among women receiving HRT, those with APOE*4 gain more bone mineral than other women.

Dietary patterns and mortality in Danish men and women: a prospective observational study

The analysis of dietary patterns emerged recently as a possible approach to examining diet-disease relation. We analysed the risk of all-cause and cardiovascular mortality associated with dietary patterns in men and women, while taking a number of potential confounding variables into account. Data were from a prospective cohort study with follow-up of total and cause-specific mortality. A random sample of 3698 men and 3618 women aged 30-70 years and living in Copenhagen County, Denmark, were followed from 1982 to 1998 (median 15 years). Three dietary patterns were identified from a twenty-eight item food frequency questionnaire, collected at baseline: (1) a predefined healthy food index, which reflected daily intakes of fruits, vegetables and wholemeal bread, (2) a prudent and (3) a Western dietary pattern derived by principal component analysis. The prudent pattern was positively associated with frequent intake of wholemeal bread, fruits and vegetables, whereas the Western was characterized by frequent intakes of meat products, potatoes, white bread, butter and lard. Among participants with complete information on all variables, 398 men and 231 women died during follow-up. The healthy food index was associated with reduced all-cause mortality in both men and women, but the relations were attenuated after adjustment for smoking, physical activity, educational level, BMI, and alcohol intake. The prudent pattern was inversely associated with all-cause and cardiovascular mortality after controlling for confounding variables. The Western pattern was not significantly associated with mortality. This study partly supports the assumption that overall dietary patterns can predict mortality, and that the dietary pattern associated with the lowest risk is the one which is in accordance with the current recommendations for a prudent diet.

Estimation of apolipoprotein E genotype-specific relative mortality risks from the distribution of genotypes in centenarians and middle-aged men: apolipoprotein E gene is a "frailty gene," not a "longevity gene"

We developed a method to estimate genotype-specific average relative mortality risk, R, from genotype distributions in cross-sectional studies of people belonging to different age-groups, and applied the method to new data from a study of apolipoprotein E genotypes (apoE) in 177 Danish centenarians and data from a study of 40-year-old Danish men. Twenty-one percent of the centenarians were epsilon 2-carriers (genotypes epsilon 2 epsilon 2 and epsilon 3 epsilon 2) and 15% were epsilon 4-carriers (genotypes epsilon 4 epsilon 4 and epsilon 4 epsilon 3) compared to 13 and 29%, respectively, of the young men. The R-values were 0.95 (95% CI 0.88 to 1.02) for epsilon 2-carriers and 1.13 (95% CI 1.05 to 1.22) for epsilon 4-carriers, using epsilon 3 epsilon 3- and epsilon 4 epsilon 2 genotypes as reference. Corresponding values for epsilon 4-carriers were obtained by using published data from a French and a Finnish study of centenarians, whereas the values for epsilon 2-carriers were about 0.90 with these data. The method to estimate mortality risk and the results associate with the view that the apoE gene is a "frailty gene." On the other hand, if odds ratios are used to summarize data from studies of this kind, they are more impressive and may propagate the misconception that apoE is a "longevity gene".

Apolipoprotein E genotype is associated with differential expansion rates of small abdominal aortic aneurysms

BACKGROUND

The common polymorphism of the apolipoprotein E (APOE) gene is associated with differential risk of atherosclerosis; the gene could be a candidate gene in abdominal aortic aneurysms (AAA).

METHODS

APOE genotypes were determined in 57 men aged 65-73 years with a small AAA (30-50 mm). The patients were included in a population ultrasonographic screening programme and were followed with at least two examinations during an interval of 2-4.5 years. The AAA expansion rates in patients with four different APOE genotypes were studied, with adjustment for initial AAA size and smoking.

RESULTS

APOE genotype was a significant determinant of AAA expansion rate (P = 0.001). The adjusted mean (95 per cent confidence interval) rate was 2.1 (1.7-2.6) mm/year in 31 men with genotype E3E3, 1.3 (0.7-1.9) mm/year in 17 men with E3E4, 3.1 (2.0-4. 1) mm/year in six men with E2E3 and 4.2 (2.7-5.6) mm/year in three men with E2E4. The mean expansion rate was 2.2 (1.5-2.8) mm/year in non-smokers and 3.0 (2.5-3.6) mm/year in smokers (P = 0.014).

CONCLUSION

APOE genotype seems to influence AAA expansion rate, but the effects of the individual genotypes, in particular E3E3 and E3E4, are contradictory when compared with the effects of the genotypes on risk of atherosclerosis.

Trends in selected biological risk factors for cardiovascular diseases in the Danish MONICA population, 1982-1992

Data from 6695 men and women of ages 30, 40, 50, and 60 years, examined in the Danish WHO MONICA surveys in 1982-84, in 1986-87, and in 1991-92, were analyzed to estimate secular trends in body height and weight, blood pressure, and serum total, HDL-, and LDL-cholesterol, and triglyceride. Body height increased 0.1% per year, and body mass index increased 0.4% per year in women. Diastolic blood pressure increased 0.4% per year in women and 0.6% per year in 60-year-old men. HDL cholesterol declined 0.4% per year. Body mass indices in men, diastolic blood pressures in men <60 years of age, systolic blood pressures, total- and LDL cholesterol and triglyceride did not change. The levels of biological risk factors in the Danish WHO MONICA study population did not show trends during the 1980s that help explain the declining incidence of myocardial infarction in the population.

Association of coronary heart disease with age-adjusted aortocoronary calcification in patients with familial hypercholesterolaemia

OBJECTIVES

Existing algorithms of risk of coronary heart disease (CHD) do not pertain to patients with familial hypercholesterolaemia (FH), whose arteries have been exposed to hypercholesterolaemia since birth. We studied a cohort of FH patients to compare four diagnostic models of CHD: traditional risk factors of CHD (age, sex, cholesterol, hypertension, smoking and body mass index), cholesterol year score, and aortic as well as coronary calcium measured by spiral computed tomography (CT).

SUBJECTS

We invited 88 individuals with molecularly defined FH of whom 80 (91%) decided to participate.

RESULTS

Analysis of receiver operating characteristic curves showed that the age-adjusted coronary calcium score was more strongly associated with clinical manifestations of CHD than were traditional risk factors (P < 0.002), cholesterol year score (P << 0.0001), and the age-adjusted aortic calcium score (P < 0.0004).

CONCLUSIONS

Age-adjusted coronary calcium score shows promise as an indicator of CHD in FH patients.

The marker of cobalamin deficiency, plasma methylmalonic acid, correlates to plasma creatinine

OBJECTIVE

To examine the relationship between the two diagnostic tests, plasma methylmalonic acid and plasma cobalamins, and their association with plasma creatinine, age and sex.

DESIGN

Cross-sectional study of simultaneous laboratory measurements.

SETTING

County of Aarhus, Denmark.

SUBJECTS

Records on 1689 patients who had their first plasma methylmalonic acid measurement during 1995 and 1996, and who had a simultaneous measurement of plasma cobalamins. Plasma creatinine values measured within a week of measurements of plasma methylmalonic acid and plasma cobalamins were available for 1255 of the patients.

MAIN OUTCOME MEASURES

Predictors of variation in plasma methylmalonic acid; plasma cobalamins, plasma creatinine, age and sex.

RESULTS

Plasma methylmalonic acid was positively correlated with plasma creatinine, even for plasma creatinine within the normal range. These associations remained in a multiple regression analysis. For plasma cobalamins below 200 pmol L-1, there was a strong negative correlation between plasma methylmalonic acid and plasma cobalamins, whilst the association was weak for higher plasma cobalamin levels. Plasma methylmalonic acid increased and plasma cobalamins decreased with age.

CONCLUSIONS

The strong correlation between plasma methylmalonic acid and plasma creatinine suggests that plasma creatinine - also within the normal range - must be taken into consideration when interpreting plasma methylmalonic acid.

The apolipoprotein epsilon4 allele determines prognosis and the effect on prognosis of simvastatin in survivors of myocardial infarction : a substudy of the Scandinavian simvastatin survival study

BACKGROUND

Carriers of the epsilon4 allele of the apolipoprotein E gene are at a higher risk of coronary heart disease than individuals with other genotypes. We examined whether the risk of death or a major coronary event in survivors of myocardial infarction depended on apolipoprotein E genotype and whether the benefits of treatment with simvastatin differed between genotypes.

METHODS AND RESULTS

Cox proportional hazards models were used to analyze 5.5 years of follow-up data from 966 Danish and Finnish myocardial infarction survivors enrolled in the Scandinavian Simvastatin Survival Study. A total of 16% of the 166 epsilon4 carriers in the placebo group died compared with 9% of the 312 patients without the allele, which corresponds to a mortality risk ratio of 1.8 (95% confidence interval, 1.1 to 3.1). The risk ratio was unaffected by considerations of sex, age, concurrent angina, diabetes, smoking, and serum lipids in multivariate analyses. Simvastatin treatment reduced the mortality risk to 0.33 (95% confidence interval, 0.16 to 0.69) in epsilon4 carriers and to 0.66 (95% confidence interval, 0. 35 to 1.24) in other patients (P=0.23 for treatment by genotype interaction). Apolipoprotein E genotype did not predict the risk of a major coronary event. Baseline serum levels of lipoprotein(a) also predicted mortality risk and could be combined with epsilon4-carrier status to define 3 groups of patients with different prognoses and benefits from treatment.

CONCLUSIONS

Myocardial infarction survivors with the epsilon4 allele have a nearly 2-fold increased risk of dying compared with other patients, and the excess mortality can be abolished by treatment with simvastatin.

Physicians' use of plasma methylmalonic acid as a diagnostic tool

OBJECTIVES

To investigate physicians' reasons for requesting plasma methylmalonic acid and their reactions to an increased concentration of plasma methylmalonic acid.

DESIGN

Study of medical records.

SETTING

Three somatic district hospitals in Denmark.

SUBJECTS

Medical records of 198 patients with a plasma methylmalonic acid measurement above the reference interval. Information on diagnostic decisions was available for 177 patients.

MAIN OUTCOME MEASURES

Reasons for requesting plasma methylmalonic acid and the reactions to the finding of elevated plasma methylmalonic acid.

RESULTS

An explicit reason for requesting plasma methylmalonic acid was stated in 57% of 198 examined medical records, known or suspected anaemia being the most frequent reason. No further action was taken in 109 (62%) of the 177 cases available for follow-up. Amongst the remaining 68 patients, the finding of an increased plasma methylmalonic acid led to diagnosis of cobalamin deficiency in 46 patients. Six patients with a markedly increased plasma methylmalonic acid (above 0.99 micromol L-1) and clearly decreased plasma cobalamins (below 200 pmol L-1) were not recognized as having cobalamin deficiency.

CONCLUSIONS

This lack of response to an increased plasma methylmalonic acid raises an important question. Is the clinical response inadequate, or is the connection between an increased level of plasma methylmalonic acid and signs of clinical significant cobalamin deficiency less clear?

Socioeconomic status and trends in risk factors for cardiovascular diseases in the Danish MONICA population, 1982-1992

STUDY OBJECTIVE

The decline in cardiovascular mortality in Denmark during the 1980s has been greatest in the highest socioeconomic groups of the population. This study examines whether the increased social inequality in cardiovascular mortality has been accompanied by a different trend in cardiovascular risk factors in different educational groups.

DESIGN

Data from three cross sectional WHO MONICA surveys conducted in 1982-84, 1987, and 1991-92, were analysed to estimate trends in biological (weight, height, body mass index, blood pressure, and serum lipids) and behavioural (smoking, physical activity during leisure, and eating habits) risk factors in relation to educational status.

SETTING

County of Copenhagen, Denmark.

PARTICIPANTS

6695 Danish men and women of ages 30, 40, 50, and 60 years.

MAIN RESULTS

The prevalence of smoking and heavy smoking decreased during the study but only in the most educated groups. In fact, the prevalence of heavy smoking increased in the least educated women. There was no significant interaction for the remaining biological and behavioural risk factors between time of examination and educational level, indicating that the trend was the same in the different educational groups. However, a summary index based on seven cardiovascular risk factors improved, and this development was only seen in the most educated men and women.

CONCLUSION

The difference between educational groups in prevalence of smoking increased during the 1980s, and this accounted for widening of an existing social difference in the total cardiovascular risk.

C-reactive protein and bacterial meningitis: a meta-analysis

The aim of the study was to review published articles on the diagnostic accuracy of C-reactive protein (CRP) tests with cerebrospinal fluid and serum in diagnosing bacterial meningitis. The literature from 1980 and onwards was searched using the electronic databases of MEDLINE, and we used summary receiver operating characteristic curve analyses (SROCs) to describe central tendencies and examine possible sources of inter-study variability in the results. We included data from 35 studies of both children and adults: 21 in which CRP had been measured in cerebrospinal fluid, 10 in which CRP had been measured in serum, and 4 in which it had been measured in both cerebrospinal fluid and serum. The odds ratio for bacterial meningitis versus aseptic meningitis for a positive CRP test with cerebrospinal fluid was estimated at 241 (95% confidence interval [CI]: 59-980), and the central tendencies for the true-positive fraction (sensitivity) and the false-positive fraction (1-specificity) were estimated at 0.94 and 0.06, respectively. The corresponding figures for a CRP test with serum were 150 (95% CI: 44-509), 0.92 and 0.08, respectively. Regression analyses including variables coding for study design features, inclusion of neonatal patients, geographical region, or use of a quantitative biochemical method did not indicate statistically significant contributions to inter-study variances in the log odds ratios. For values of the true- and the false-positive fractions of 0.92-0.94 and 0.06-0.08, respectively, the post-test probability of not having bacterial meningitis given a negative test is very high (> or = 97%), in the range of a pre-test probability (prevalence of bacterial meningitis) from 10 to 30%, whereas the post-test probability of bacterial meningitis given a positive test is considerably lower. Hence, only a negative test is highly informative in a typical clinical setting. This, as well as the absence of analyses to show if CRP tests contribute independent diagnostic information, relatively to the information held in the traditionally used clinical and biochemical variables, makes it difficult to conclude on the clinical usefulness of CRP tests in the management of patients suspected of having bacterial meningitis.

Glucose metabolism, lipid metabolism, and cardiovascular risk factors in adult Turner's syndrome. The impact of sex hormone replacement

OBJECTIVE

To examine glucose metabolism, blood pressure, physical fitness, and lipid metabolism in adult untreated women with Turner's syndrome compared with a group of normal women and to examine the effects of female sex hormone substitution on these factors.

RESEARCH DESIGN AND METHODS

A total of 26 patients with Turner's syndrome were examined before and during sex hormone replacement with 17 beta-estradiol and norethisterone, and an age-matched control group (n = 24) was examined once. A frequently sampled intravenous glucose tolerance test was applied with minimal model assessment. We also performed an oral glucose tolerance test, measurement of 24-h ambulatory blood pressure, and assessment of physical fitness and lipid metabolism.

RESULTS

Insulin sensitivity (SI) and glucose effectiveness (SG) were similar in Turner's syndrome patients and control subjects, whereas the acute insulin response (P = 0.03) was lower in Turner's syndrome patients, and no change was seen during sex hormone treatment. Abnormal glucose tolerance was found in 50% of Turner's syndrome patients before and 78% during treatment with sex hormones. Fat-free mass (FFM; P = 0.0005) and physical fitness (P = 0.002) were lower in Turner's syndrome subjects compared with control subjects. During treatment, an increase in FFM (P = 0.001) and physical fitness (P = 0.02) was seen in Turner's syndrome patients. Blood pressure was increased in Turner's syndrome, and a decrease was seen in diastolic blood pressure during treatment with sex hormones.

CONCLUSIONS

Turner's syndrome is associated with glucose intolerance, diminished first-phase insulin response, elevated blood pressure, reduced FFM, and physical fitness. Sex hormone administration causes a deterioration in glucose tolerance, increases FFM and physical fitness, and has beneficial effects on blood pressure. The deleterious effect on glucose tolerance may be mediated by norethisterone, a gestagen known to have androgenic effects.

Apolipoprotein(a) isoforms and coronary heart disease in men: a nested case-control study

The objective of the present study was to examine the possible associations between low molecular weight (LMW) apolipoprotein(a) (apo(a)) isoforms (F,B,S1,S2) and coronary heart disease (CHD). We conducted a nested case-control (prospective) study of five cohorts of white men: The 1936 cohort (baseline 1976, n = 548) and four cohorts from MONICA I born in 1923 (n = 463), 1933 (n = 491), 1943 (n = 504) and 1953 (n = 448) studied at baseline in 1983. At follow up in 1991, 52 subjects had developed a first myocardial infarction and 22 had been hospitalized with angina pectoris. Plasma samples obtained at baseline were stored frozen until 1993-94, when case samples (n = 74) were analyzed together with samples from matched (disease free) controls (n = 190). In a statistical model (conditional logistic regression) including all age groups, cholesterol (or apo B) level (P < 0.01), systolic blood pressure (P = 0.05) and smoking (P = 0.02) predicted CHD. In the statistical model Lp(a) interacted significantly with age (OR = 5.7; 95% CI: 1.4-23.6; P = 0.016), and high Lp(a) (over 45 mg/dl) was associated with significantly increased risk in subjects under 60 years (OR = 3.82; 95% CI: 1.47-9.96), but not in older men (OR = 0.67; 95% CI: 0.235-1.89). Therefore, we studied the impact of Lp(a)/apo(a) and other variables in subjects who had been under 60 years when they became cases. Among the younger subjects the presence of LMW apo(a) isoforms significantly predicted the development of CHD (OR = 3.83; 95% CI: 1.18-12.4). The increased risk pertained to high Lp(a) (above versus below 45 mg/dl: OR = 3.68; 95% CI: 1.03-13.10), and to Lp(a) concentrations when entered into the model as a continuous variable (P = 0.04). Cholesterol or apo B (P < 0.01), smoking (P = 0.02), systolic blood pressure (P = 0.05) and low alcohol consumption (under nine drinks/week) (P = 0.04) were also significant predictors of CHD. We conclude that LMW apo(a) isoforms are significantly associated with increased risk of CHD in men under 60 years.

Phenotypic variation in patients heterozygous for familial defective apolipoprotein B (FDB) in three European countries

A glutamine-for-arginine substitution at amino acid position 3500 of apolipoprotein B (apo B) causes synthesis of LDL with reduced binding affinity to the LDL receptor (LDLR). The associated clinical syndrome has been named familial defective apolipoprotein B- 100 (FDB). In 205 FDB patients from Germany (n = 73). The Netherlands (n = 87), and Denmark (n = 45), we tried to assess determinants of variation in lipid concentrations. Besides age, sex, and geographic origin, variation in the LDLR gene was the most powerful determinant of variation in total cholesterol and LDL cholesterol levels. Polymorphic variation in the LDLR gene (SfaNI, exon 2; Nco I, exon 18) was associated with total cholesterol (TC) and LDL cholesterol (LDL-C) variation in women (SfaNI: P = .04 and .03 for TC and LDL-C, respectively; Nco I; P = .003 and .006, respectively), whereas the Ava II (exon 13) and the Pvu II (intron 15) polymorphisms were not. Combined information from all three LDLR exon polymorphisms showed that subjects with at least one S + A + N + allele had 13% to 20% higher TC than non-S + A + N + subjects (P = .02 [TC, men]; P = .01 [LDL-C, men]; P = .005 [TC, women]; and P = .004 [LDL-C, women]) and, together with age and geographic origin, accounted for 20% (women) and 19% (men) of the variation in LDL-C. The expected association of the apo E genotypes (e3e2, e3e3, and e3e4) with cholesterol concentrations was seen in S + A + N + but not in non-S + A + N + subjects and in P-P- but not in P + P + or P + P- subjects. With regard to clinical expression, FDB patients had lower TC and LDL-C levels and a lower prevalence of cardiovascular disease than 101 Danish patients with familial hypercholesterolemia.

Effects of apoE gene polymorphism on Lp(a) concentrations depend on the size of apo(a): a study of 466 white men

Polymorphisms in the genes for the low-density lipoprotein (LDL) receptor ligands, apolipoprotein E (apoE), and apolipoprotein B (apoB) are associated with variation in plasma levels of LDL cholesterol. Lp(a) lipoprotein(a) [Lp(a)] is LDL in which apoB is attached to a glycoprotein called apolipoprotein(a) [apo(a)]. Apo(a) has several genetically determined isoforms differing in molecular weight, which are inversely correlated with Lp(a) concentrations in blood. The interaction of apo(a) with triglyceride-rich lipoproteins differs with the size of apo(a), and therefore the effects of apoE gene polymorphism on Lp(a) levels could also depend on apo(a) size. We have investigated the possible effect of genetic variation in the apoE and apoB genes on plasma Lp(a) concentrations in 466 white men with different apo(a) phenotypes. Overall there was no significant association between the common apoE polymorphism and Lp(a), but in the subgroup with apo(a)-S4, concentrations of Lp(a) differed significantly among the apoE genotypes (P = 0.05). Lp(a) was highest in the apoE genotypes epsilon 2 epsilon 3 and epsilon 3 epsilon 3 and lowest in genotype epsilon 3 epsilon 4, and the apoE polymorphism was estimated to account for about 2.4% of the variation in Lp(a). In contrast, in the subgroup with apo(a)-S2 Lp(a) was significantly lower (P = 0.04) in apoE genotype epsilon 2 epsilon 3 than in genotype epsilon 3 epsilon 3. Lp(a) concentrations did not differ among the XbaI (P = 0.65) or SP 24/27 (P = 0.26) polymorphisms of the apoB gene. The expected effects of both apoE and apoB polymorphism on LDL levels were significant in the whole population sample and in subjects with large-sized apo(a) isoforms (P < 0.01), whereas no effect was seen in those with low molecular weight apo(a) isoforms. We conclude that the influence of apoE genotypes on Lp(a) concentrations depends on the size of the apo(a) molecule in Lp(a), possibly because both apo(a)-S4 and apoE4 have high affinity for triglyceride-rich lipoproteins and may be taken up and degraded rapidly by remnant receptors.

The apolipoprotein E polymorphism in Greenland Inuit in its global perspective

Apolipoprotein E (apoE) genotypes were determined in Inuit population samples from Nuuk on the south-west coast of Greenland (n = 100) and from the Ammassalik region on the south-east coast (n = 78). The epsilon 2 allele was absent in the latter sample, and the epsilon 4 allele frequency was relatively high, about 23%. As in most other populations, mean plasma lipoprotein-related variables, except high-density lipoprotein (HDL) cholesterol, were higher in both Inuit men and women with epsilon 4 than in epsilon 3 epsilon 3 genotypes (P < 0.05 for triglycerides in men, and for non-HDL cholesterol and apolipoprotein B in women). The estimated apoE allele frequencies were combined with data from other studies of aboriginal peoples to outline a world map of apoE allele frequencies. A recent study of non-human primates suggests that epsilon 4, and not epsilon 3, is the ancestral allele in humans and we have used the map to generate additional hypotheses regarding the history of the apoE polymorphism in humans.

Are men carrying the apolipoprotein epsilon 4- or epsilon 2 allele less fertile than epsilon 3 epsilon 3 genotypes?

The epsilon 3 allele in the human gene coding for apolipoprotein E (apoE) is the most common worldwide, but epsilon 4 is probably the ancestral allele. Since apoE is involved in many important biological processes, selection forces could have favoured epsilon 3. We hypothesized that apoE genotypes may affect reproductive efficiency, and we therefore compared the distributions of 40-year-old married men with known genotypes by the numbers of their biological children. The distributions were statistically significantly different (P = 0.0026). On average, men with the epsilon 3 epsilon 3 genotype (n = 212) had 1.93 children, men with the epsilon 3 epsilon 4 or epsilon 4 epsilon 4 genotype (n = 105) had 1.50, and men with the epsilon 3 epsilon 2 or epsilon 2 epsilon 2 genotypes (n = 53) had 1.66 children. Of the men in the three groups, 6%, 26% and 19%, respectively, reported being childless. These findings are unlikely to be due to gross error in the reported prevalence of childlessness, differences in socioeconomic status or other likely sources of bias. They are compatible with higher fertility in men with the epsilon 3 epsilon 3 genotype than in those with the other common apoE genotypes.

Polymorphisms in the lipoprotein lipase gene and their associations with plasma lipid concentrations in 40-year-old Danish men

BACKGROUND

In some previous studies, HindIII and Pvu II restriction fragment length polymorphisms (RFLPs) in the lipoprotein lipase (LPL) gene were associated with coronary heart disease and plasma concentrations of HDL cholesterol and triglycerides. However, the populations studied were relatively small and heterogeneous in regard to age, sex, and ethnic background.

METHODS AND RESULTS

Associations of a HindIII (intron 8) and a Pvu II (intron 6) RFLP in the LPL gene with plasma concentrations of cholesterol, HDL cholesterol, non-HDL cholesterol, and triglycerides were studied in 457 randomly selected 40-year-old Danish men. The HindIII and the Pvu II sites were in strong linkage disequilibrium. The frequencies of the H+ and P+ alleles (+ denotes presence of cutting site) were 0.717 and 0.464, respectively. In multivariate analysis, there was a clear gene dosage effect of the H+ allele on HDL. The lowest HDL cholesterol concentration was in the H+H+ group, the highest concentration was in the H-H- group, and the H+H- group had intermediate HDL concentrations (P = .03). There was a similar, but not statistically significant gene dosage effect on triglyceride concentrations, with the highest value seen in the H+H+ group. There were no other associations between LPL RFLPs and lipoprotein components. In males reporting family history of premature ischemic heart disease, the H+H+ genotype was overrepresented (odds ratio, 2.75; 95% confidence interval, 1.37 to 5.53).

CONCLUSIONS

The results suggest that genetic variation in or near the LPL gene plays a role in interindividual differences in HDL cholesterol concentration and in risk of atherosclerosis and ischemic heart disease in men.

A unique pattern of apo(a) polymorphism in an isolated east Greenlandic Inuit (Eskimo) population

Eskimos of the east coast of Greenland very rarely had contacts with Caucasians until late in the 19th century. Their genes are therefore likely to be similar to those in the original Eskimo gene pool. We have compared serum concentrations of Lp(a) and apo(a) phenotypes in 78 East Greenland Eskimos (EGE) with those in Eskimos from Western Greenland (WGE) (n = 100) and Caucasian Danes (n = 466). Lp(a) levels were higher in EGE (median: 11.9 mg/dl [95% CI: 9.1-16.4]) than in Danes (p < 0.01), (median: 6.3 mg/dl [95% CI: 5.5-7.3]) and WGE (p < 0.01), (median: 7.8 mg/dl [95% CI: 5.7-10.2]). Lp(a) concentrations above 30 mg/dl were (p < 0.05) more common in EGE (19%) than in WGE (9%) and similar (p = 0.89) to those in Danes (20%). Apo(a) molecules as small as S2 or smaller (S1, B and F) were present in 26% of Danes and in 3% of WGE but were absent in EGE (p < 0.01). In contrast, a large apo(a) variant (VS4) was present in 54% of EGE and 62% of WGE, whereas it was very rare in Danes (2%). Lp(a) concentrations were inversely associated with apo(a) size in EGE (p < 0.05), WGE (p < 0.01) and Danes (p < 0.01), but EGE with S3 or S4 had significantly higher Lp(a) levels than Danes (p < 0.05) with the same phenotypes.

Hypocholesterolaemic effect of a new fermented milk product in healthy middle-aged men

OBJECTIVE

There are still controversies as to the potential beneficial effects of milk and fermented milk products on the level of lipoproteins. The objective of the present investigation was to test the effect of a moderate daily intake of a new fermented milk product, which was based on a bacterial culture obtained from the intestinal flora of inhabitants of Abkhasia, on the lipoprotein levels of a homogeneous group of middle-aged Danish men.

DESIGN

The study was randomised, double-blind, and placebo-controlled, and the intervention was performed for a period of 6 weeks.

SUBJECTS

Fifty-eight healthy, non-obese, normocholesterolaemic, male volunteers born in 1949 of Danish descent participated (i.e. all were 44 years old).

INTERVENTIONS

During the intervention period the subjects' habitual diets were supplemented with 200 ml/day of either the new fermented milk product or a placebo product (chemically fermented). The biologically fermented milk product contained Enterococcus faecium and two strains of Streptococcus termophilus. Fasting blood samples were drawn initially and after 3 and 6 weeks and analysed for plasma values of total cholesterol, high-density lipoprotein (HDL)-cholesterol and triglyceride. In addition, LDL-cholesterol was estimated.

RESULTS

After these 6 weeks total cholesterol was reduced significantly in the group given biologically fermented milk (-0.37 mmol/l, confidence interval: -0.51 to -0.23) while no changes were observed in the placebo group (-0.02 mmol/l) (P < 0.01). This reduction in total cholesterol could be completely ascribed to a fall in LDL-cholesterol by 10% (i.e. -0.42 mmol/l) since HDL-cholesterol and triglyceride were unchanged in both groups.

CONCLUSIONS

Thus, this short-term study (6 weeks) demonstrated an LDL-cholesterol-lowering effect (10% reduction) of a new fermented milk product in middle-aged Danish men.

Apolipoprotein(a) phenotypes and lipoprotein(a) concentrations in patients with hyperthyroidism

Lipoprotein(a) [Lp(a)] is a low-density lipoprotein (LDL) particle in which apolipoprotein B-100 (apoB) is attached to a glycoprotein called apolipoprotein(a) [apo(a)]. Apo(a) has several genetically determined phenotypes differing in molecular weight, to which Lp(a) concentrations in plasma are inversely correlated. High plasma levels of Lp(a) are associated with atherosclerotic diseases. It is therefore of interest to study whether factors other than the apo(a) gene locus are involved in the regulation of Lp(a) concentrations. We measured plasma concentrations of Lp(a) and other lipoproteins and determined apo(a) phenotypes in 31 patients with hyperthyroidism, before and after the patients had become euthyroid by treatment. The mean concentration of LDL cholesterol rose from 2.67 to 3.88 mmol/l (P < 0.01), apoB rose from 0.79 to 1.03 g/l (P < 0.01), and the median Lp(a) concentration increased from 9.74 to 18.97 mg/dl (P < 0.01) on treatment. Lp(a) concentrations were inversely associated to the size of the apo(a) molecule both before (P < 0.01) and after treatment (P < 0.01). The increase in Lp(a) was significant in patients with high molecular weight apo(a) phenotypes (n = 9; P < 0.01) and in patients with low molecular weight apo(a) phenotypes (n = 16; P < 0.01), but not in those with apo(a) "null types" (n = 6; P = 0.5). The low levels LDL cholesterol and apoB in untreated hyperthyroidism may result from increased LDL receptor activity. The increase in Lp(a) levels were not correlated with the increase in LDL cholesterol or apoB.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of patients with familial defective apolipoprotein B-100 with pravastatin and gemfibrozil: a two-period cross-over study

Thirty patients with familial defective apolipoprotein B-100 were treated in a two-period (8 weeks each) cross-over study with pravastatin and gemfibrozil. Cholesterol, LDL cholesterol, and apo B were reduced by 20-25% (P < 10(-4)) by pravastatin and by 4-6% by gemfibrozil (pravastatin vs. gemfibrozil: P < 10(-4)). Response to pravastatin was variable and not correlated to gender, age, or apo E genotype. Gemfibrozil lowered triglycerides by 25% (P < 10(-4)) and raised HDL cholesterol by 11%. The effects of pravastatin on these two interrelated variables were significantly smaller. Both drugs increased Lp(a) significantly by about 10%. The LDL cholesterol lowering effect of pravastatin in patients with FDB is similar to that observed in patients with familial hypercholesterolemia.

Incidence of the apolipoprotein B-3500 mutation in Denmark

A total of 5000 consecutively samples newborn screening cards were anonymously selected for screening for the apolipoprotein B-3500 (apo B-3500) mutation, which causes familial defective apolipoprotein B-100 (FDB). The mutation was found in 5 of 5000 Danish children, of whom 2 were twins. This indicates a lower prevalence of this mutation in Danes than that reported in the UK, Germany, USA, Austria, Canada and especially Switzerland. Haplotype studies suggest that Caucasian subjects with the apo B-3500 mutation have a common founder. The apparently lower prevalence in Denmark than in Switzerland and Central Europe may indicate that the mutation was brought from these areas to Denmark after the initial settling of Denmark. In 101 unrelated Danish subjects with familial hypercholesterolemia, diagnosed on clinical and biochemical criteria including tendon xanthomata, 2 were heterozygous for the apo B-3500 mutation (2%).

Apolipoprotein B gene polymorphisms in ischemic heart disease and hypercholesterolemia: effects of age and sex

The association of polymorphic alleles of the apolipoprotein B gene (Insertion/Deletion-, XbaI-, MspI-, EcoRI-, and 3'-VNTR polymorphisms) with variation in lipid concentrations (total cholesterol (T-C), HDL cholesterol (HDL-C), and log-triglycerides (TG)) in plasma was studied in 259 men and 59 women with moderate hypercholesterolemia (T-C 5.5-8.0 mmol/l and TG < 2.5 mmol/l) and ischemic heart disease, especially in relation to the effect of sex and age. The XbaI and the Ins/Del polymorphic alleles were associated with variation in T-C, but only in patients below the 75th percentile for age. The XbaI and Ins/Del polymorphic alleles were synergistically associated with variation in T-C: the X+ and the Del alleles were associated with higher cholesterol concentrations. Younger male patients had the highest frequency of haplotypes including both the X+ and the Del alleles, but the most striking difference was a significantly higher frequency of haplotypes including both the X- and the Ins alleles in female and in older male patients. The heterogeneity of association of polymorphic alleles in the apolipoprotein B gene to complex traits like hypercholesterolemia and ischemic heart disease in this study could explain why in most studies the X+ allele has been associated with higher cholesterol levels, whereas the X- allele has been associated with symptomatic atherosclerosis. The results of our study emphasize the importance of age and sex in measured genotype association studies.

Genotyping compared with protein phenotyping of the common apolipoprotein E polymorphism

Apolipoprotein E (apo E) genotypes have been determined in 460 Danish men, with the use of the polymerase chain reaction (PCR) to amplify a 244 base pair fragment spanning the first-base polymorphic sites in the codons of amino acids 112 and 158 followed by restriction endonuclease cleavage. The results were compared with the apo E phenotypes previously determined by isoelectric focusing (IEF) of delipidated plasma, not pretreated with neuraminidase, followed by apo E specific immunoblotting. Conflicting results were found in only 9 cases (2.0%) and in each case only with respect to one allele. Five of the discrepancies can be explained, post hoc, by technical difficulties with the IEF method ('faint bands'). A possible cause of the other 4 discrepancies is the presence of rare mutations. Our findings in this large study are reassuring, since, if appreciable and systematic misclassification of genotypes do occur by using IEF, as has been reported from some laboratories, it may influence the validity of genetic epidemiological studies.

[Cholesterol-lowering effect of a new fermented milk product in healthy 44-year old Danish men]

The potential cholesterol-lowering effect of a new fermented milk product was tested in a homogeneous group of Danish men (all 44-year-old; n = 58) in a randomised, double blinded and placebo-controlled study. Two hundred ml of the fremented milk or placebo (chemically acidified) was taken daily for six weeks. After these six weeks total cholesterol decreased significantly in the fermented milk group by -0.37 mmol/l (confidence interval: -0.51 to -0.23 mmol/l) and no changes were observed in the placebo group (-0.02 mmol/l) (p < 0.01). This decrement in total cholesterol could be completely ascribed to a reduction of LDL-cholesterol by 10% (i.e. -0.42 mmol/l), since HDL-cholesterol and triglyceride were unchanged in both groups during the study. Thus, in the present short term study, the tested fermented milk product was able to reduce LDL-cholesterol in middle-aged men.

Genetic markers in the apo AI-CIII-AIV gene cluster for combined hyperlipidemia, hypertriglyceridemia, and predisposition to atherosclerosis

The aim of the present study was to search for genetic determinants of combined hyperlipidemia and hypertriglyceridemia, and to evaluate whether such determinants might be associated with predisposition to atherosclerosis. Four DNA polymorphisms in the apo AI-CIII-AIV gene cluster (G to A mutation at position -75 basepairs in the apo AI promoter, XmnI, PstI and SstI) were studied in relation to combined hyperlipidemia, hypertriglyceridemia, lipoprotein levels, atherosclerosis and age in 221 Danish men. The frequency of the rare allele of the XmnI polymorphism, the X+ allele, was higher in individuals below 55 years of age with combined hyperlipidemia than in individuals with normal lipid levels (0.31 vs. 0.14; P = 0.05). The rare allele of the SstI polymorphism, the S+ allele, was more frequent in hypertriglyceridemic individuals compared with normotriglyceridemic individuals (0.16 vs. 0.09; P < 0.05) and on analysis of variance the combined S-S+ and S+S+ genotypes were also associated with the highest triglyceride levels. Furthermore, the frequency of the S+ allele decreased significantly as a function of age in nonatherosclerotic subjects (from 0.15 to 0.10 to 0.02 in 48-, 63- and 85-year-olds, respectively; 48- versus 85-year-olds, P = 0.03). These results suggest that genetic variation in the apo AI-CIII-AIV gene complex is associated with combined hyperlipidemia and hypertriglyceridemia and may have an impact on longevity and/or predisposition to atherosclerosis.

Apolipoprotein(a) polymorphism predicts the increase of Lp(a) by pravastatin in patients with familial hypercholesterolaemia treated with bile acid sequestration

HMG-CoA reductase inhibitors effectively reduce the concentration of low density lipoproteins (LDL) in plasma. Lipoprotein(a) [Lp(a)] may be as atherogenic as LDL. A few studies, only one of which was placebo controlled, suggest that the HMG CoA reductase inhibitors either do not affect Lp(a) or they increase Lp(a). The response of Lp(a) to HMG-CoA reductase inhibition has not been related to apolipoprotein(a) phenotypes in previous studies. We conducted a double-blind, placebo controlled study of pravastatin in 51 patients with familial hypercholesterolemia (FH) (n = 43) or probable FH (n = 8). All patients had LDL-cholesterol concentration above 4.1 mmol l-1 despite treatment with diet and bile acid sequestration. In patients assigned to pravastatin (n = 34), the mean concentrations of total cholesterol and LDL cholesterol fell significantly (P < 0.01) when compared to placebo. Lp(a) increased (P < 0.01) from a mean (+/- SD) of 33.6 +/- 40.8 mg dl-1 to 41.1 +/- 46.1 mg dl-1 on pravastatin but was unchanged during placebo treatment. The percentage increase in Lp(a) was the same in patients with different apo(a) phenotypes, and hence the absolute increase in Lp(a) was greatest in patients with the low molecular weight apo(a) phenotypes.

A PvuII polymorphism of the low density lipoprotein receptor gene is not associated with plasma concentrations of low density lipoproteins including LP(a)

Lipoprotein(a) [Lp(a)] is a low density lipoprotein (LDL), in which apolipoprotein B-100 (apo B-100) is attached to apolipoprotein(a) [apo(a)], a glycoprotein of variable size. Lp(a) may be as atherogenic as LDL. In normal populations, Lp(a) concentrations in plasma are largely determined by the apo(a) gene locus on chromosome 6, but regulation of synthesis and catabolism of Lp(a) is poorly understood. In some studies, a PvuII restriction fragment length polymorphism (RFLP) in the LDL receptor gene seems to affect concentrations of LDL in plasma, and other studies have indicated that Lp(a) catabolism could be mediated by the LDL receptor. We therefore expected that the PvuII polymorphism in the LDL receptor gene might be associated with Lp(a) levels in 170 Caucasian men aged 40 years, selected to have a high representation of low molecular weight apo(a) phenotypes. However, plasma concentrations of cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides and Lp(a) were all unrelated to the LDL receptor gene PvuII polymorphism both in the group as a whole and when it was subgrouped by apo(a) phenotype. Therefore our data do not support the concept that this particular LDL receptor gene polymorphism is associated with LDL receptor function, and our data therefore neither support nor rule out a role for the LDL receptor in Lp(a) catabolism.