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Biomedical subjects

P Knekt

Publications and source records attributed to P Knekt.

At least 37 records · Page 2Linked to original sources
PubMed2001

Mental disorders and cause-specific mortality.

BACKGROUND: The impact of clinically diagnosed mental disorders on mortality in the general population has not been established. Aims To examine mental disorders for their prediction of cause-specific mortality. METHOD: Mental disorders were determined using the 36-item version of the General Health Questionnaire and the Present State Examination in a nationally representative sample of 8000 adult Finns. RESULTS: During the 17-year follow-up period 1597 deaths occurred. The presence of a mental disorder detected at baseline was associated with an elevated mortality rate. The relative risk in men was 1.6(95% confidence interval 1.3-1.8) and in women, 1.4 (95% Cl 1.2-1.6). In men and women with schizophrenia the relative risks of death during the follow-up period were 3.3 (95% Cl 2.3-4.9) and 2.3 (95% Cl 1.3-3.8) respectively, compared with the rest of the sample. In both men and women with schizophrenia the risk of dying of respiratory disease was increased, but the risk of dying of cardiovascular disease was increased only in men with neurotic depression. CONCLUSIONS: Schizophrenia and depression are associated with an elevated risk of natural and unnatural deaths.

Adult↗
PubMed2001

Decreasing prevalence of helicobacter antibodies in Finland, with reference to the decreasing incidence of gastric cancer.

Time trends and geographical variation of Helicobacter pylori antibodies in Finland were investigated by enzyme immunoassay in 20- to 34-year-old randomly selected females from six localities during 1969-73 (n = 375), and 15- to 45-year-old females representing nine communities and four geographical areas in 1983 (n = 882) and 1995 (n = 842). In the six communities investigated at three different time points, the overall prevalence declined from 38 to 12%, with an emphasis on the latter 12 years. The regionally varying rate of decrease in helicobacter prevalence changed the pre-existing geographical variation, leaving northern Finland with the highest rate. A 10%-units higher local helicobacter prevalence seemed to predict a 23% (95% CI 3-44%) higher gastric cancer incidence 20 years later. The overall decline in helicobacter seropositivity is consistent with earlier reports from Finland and other developed countries, and supports the cohort theory as an explanation for the age-related increase in H. pylori seroprevalence.

Adolescent↗
PubMed2000

Quercetin intake and the incidence of cerebrovascular disease.

OBJECTIVE: To study the relation between intake of the antioxidant flavonoid quercetin and subsequent incidence of cerebrovascular disease (CVA). DESIGN: A cohort study carried out among 9208 Finnish men and women 15 y or more of age and initially free from cardiovascular disease. During a 28 y follow-up period in 1967-1994, a total of 824 cases with CVA were diagnosed. METHODS: Food consumption data were collected using a dietary history interview method covering the total habitual diet during the previous year. RESULTS: Quercetin intake was not associated with CVA incidence. The relative risk of CVA adjusted for age, serum cholesterol, body mass index, smoking, hypertension, diabetes, geographical area, occupation and intake of beta-carotene, vitamin E, vitamin C, fibre, various fatty acids, and energy between the highest and lowest quartiles of quercetin intake was 0.99 (95% confidence interval (CI)=0.71-1.38) for men and 0.85 (CI=0.60-1.21) for women. In contrast, apples, the major source of quercetin in the study population, showed a significant inverse association both in men and women, mainly due to an association with thrombotic or embolic stroke. The relative risks of thrombotic stroke after further adjustment for quercetin intake were 0.59 (CI=0.35-0.99; P=0.45) and 0.61 (CI=0.33-1.12: P for trend=0.02) for men and women, respectively. CONCLUSIONS: The results suggest that the intake of apples is related to a decreased risk of thrombotic stroke. This association apparently is not due to the presence of the antioxidant flavonoid quercetin.

Aging↗
PubMed2000

Serum albumin and colorectal cancer risk.

OBJECTIVE: To study the relationship between serum albumin and colorectal cancer occurrence. DESIGN: A case-control study nested within a cohort followed from 1968 to 1991. SUBJECTS AND METHODS: The albumin concentration was determined from serum samples stored at -20 degrees C at baseline in 177 incident colorectal cancer cases and 288 controls matched for sex, age and study region. RESULTS: An elevated risk was present of cancer of the left, distal colon at high serum albumin concentrations. No significant association was observed for the right, proximal colon or the rectum. The relative risks of cancer of the distal and proximal colon among individuals in the highest and lowest quartiles of serum albumin were 17.03 (95% confidence interval 1.48-195) and 0.77 (95% confidence interval 0. 19-3.13), respectively. CONCLUSIONS: The present study lends support to the hypothesis that some dietary factor associated with serum albumin may be a risk factor for distal colon cancer.

Adult↗
PubMed2000

Heart rate and mortality.

OBJECTIVES: Increased heart rate has shown to be associated with risk of mortality from cardiovascular diseases in some studies, but not in others. Increased heart rate has also been linked to causes of death other than cardiovascular. To clarify the role of heart rate as a predictor of death we studied its predictive value in a large population study. DESIGN: A prospective population study with a follow-up time of 23 years. SUBJECTS AND METHODS: The study population comprised 5598 men and 5119 women 30-59 years of age on entry. Heart rate was measured from resting ECGs. MAIN OUTCOME MEASURE: Mortality from specified causes. RESULTS: A total of 1848 men and 840 women died during the follow-up period. Increased heart rate was significantly associated with death from all causes, cardiovascular causes, and natural noncardiovascular, nonmalignant causes of death. Increased heart rate was associated with death from cancer in men with heart disease but not in men without heart disease on entry into the study. The increase in cardiovascular mortality with high heart rate was explained by the close association between heart rate and blood pressure. Adjustment for risk factors did not alter the significance of the association between increased heart rate and mortality from noncardiovascular causes. CONCLUSIONS: High heart rate is simple to observe clinically and a significant if nonspecific predictor of mortality. Increased risk of mortality from cardiovascular diseases can be explained by association with high blood pressure. The increased mortality risk associated with high heart rate related mainly to a group of diseases of noncardiovascular or nonmalignant origin.

Adult↗
PubMed2000

Adding free to total prostate-specific antigen levels in trials of prostate cancer screening.

We used a nested case-control design on data from men in four prospective studies (from the UK, Maryland in the USA, and two from Finland) with available stored serum samples to determine whether there was an advantage in measuring both free prostate-specific antigen (PSA) and total PSA as a potential screening test for prostate cancer. Of these men, 247 were verified through national vital statistics offices as having died of prostate cancer, or having developed the disease, and 953 men who did not develop prostate cancer (controls) were selected, matched to cases for age, study centre and sample storage duration. Fixing the false-positive rate at 1%, the prostate cancer detection rate (sensitivity) over the 3 years following serum collection (based on 14 cancers) increased from an estimated 95% using total PSA to 97% using free and bound PSA (that is, bound to alpha-antichymotrypsin which together with the free form is total PSA). Over a 6-year period (based on 41 cancers) a similar difference occurred (52% and 56% detection rates respectively). We conclude that there is no material advantage in adding free to total PSA in prostate cancer screening trials.

Case-Control Studies↗
PubMed2000

Does antibacterial treatment for urinary tract infection contribute to the risk of breast cancer?

Low lignan status has been reported to be related to an elevated risk of breast cancer. Since lignan status is reduced by antibacterial medications, it is plausible to hypothesize that repeated use of antibiotics may also be a risk factor for breast cancer. History of treatment for urinary tract infection was studied for its prediction of breast cancer among 9,461 Finnish women 19-89 years of age and initially cancer-free. During a follow-up in 1973-1991, a total of 157 breast cancer cases were diagnosed. Women reporting previous or present medication for urinary tract infection at baseline showed an elevated breast cancer risk in comparison with other women. The age-adjusted relative risk was 1.34 (95% confidence interval (CI) = 0.98-1.83). The association was concentrated to women under 50 years of age. The relative risk for these women was 1.74 (95% CI 1.13-2.68), whereas it was 0.97 (95% CI 0.59-1.58) for older women. The relative risk in the younger age-group was 1.47 (95% CI 0.73-2.97) during the first 10 years of follow-up, and 1.93 (95% CI 1.11-3.37) for follow-up times longer than 10 years. These data suggest that premenopausal women using long-term medication for urinary tract infections show a possible elevated risk of future breast cancer. The results are, however, still inconclusive and the hypothesis needs to be tested by other studies.

Adult↗
PubMed2000

Type specificity and significance of different isotypes of serum antibodies to human papillomavirus capsids.

Isotype-specific serum antibody responses against human papillomavirus (HPV) type 16 were evaluated by use of cross-sectional, prospective, and population-based seroepidemiologic studies. IgG1 and IgA were the most abundant isotypes. No sample contained IgG2, and <25 samples contained IgG3 or IgM. Total IgG, IgA, and IgG1 were HPV type specific and were associated with HPV-16 DNA (odds ratios [ORs], 5.4, 5.0, and 5.9, respectively; P<.001) but not with other HPV DNA (ORs, 1.2, 1.2, and 0.8, respectively; P value was not significant). Total IgG and IgG1 were strongly associated with number of lifetime sex partners (P<.001); IgA was only associated with number of recent sex partners and lifetime sex partners among younger women. Total IgG, IgG1, and IgA were associated with cervical intraepithelial neoplasia type III and also predicted risk of future cervical neoplasia. IgG and IgG1 appeared to mark lifetime cumulative exposure, whereas IgA may mark recent or ongoing infection.

Adolescent↗
PubMed2000

Serum selenium, serum alpha-tocopherol, and the risk of rheumatoid arthritis.

Antioxidant micronutrients have been hypothesized to provide protection against rheumatoid arthritis. We investigated serum selenium and serum alpha-tocopherol for their prediction of subsequent development of rheumatoid arthritis in a case-control study nested within a Finnish cohort of 18,709 adult men and women who had neither arthritis nor a history of it at the baseline examination in 1973-1978; by late 1989, 122 had developed rheumatoid arthritis. Of the incident cases, 34 were rheumatoid factor-negative. Three controls per each incident case were individually matched for sex, age, and municipality. Serum selenium and alpha-tocopherol concentrations were measured from stored serum samples collected at baseline. Serum selenium was inversely related to subsequent occurrence of rheumatoid factor-negative but not rheumatoid factor-positive rheumatoid arthritis. The relative risks, adjusted for smoking and serum total cholesterol, for the highest relative to the lowest tertile of serum selenium, were 0.16 [95% confidence interval (CI) = 0.04-0.69] for rheumatoid factor-negative and 0.96 (CI = 0.49-1.90) for rheumatoid factor-positive rheumatoid arthritis. During the first 10 years of follow-up, the relative risk for rheumatoid arthritis for the highest compared with the lowest tertile of serum alpha-tocopherol was 0.44 (CI = 0.19-0.99). No association was found for longer follow-up periods. Low selenium status may be a risk factor for rheumatoid factor-negative rheumatoid arthritis, and low alpha-tocopherol status may be a risk factor for rheumatoid arthritis independently of rheumatoid factor status.

Adult↗
PubMed2000

Coffee consumption, rheumatoid factor, and the risk of rheumatoid arthritis.

BACKGROUND: Recent epidemiological studies have suggested that smoking is a risk factor for rheumatoid factor (RF) positive rheumatoid arthritis (RA). Being overweight, high serum cholesterol, and dietary factors have in some studies been found to be associated with the risk of RA. No attention, however, has been paid to coffee consumption as a risk determinant, though it is a shared covariate of the alleged risk factors. OBJECTIVES: This study aimed at examining coffee consumption for its associations with RF positivity and with the risk of RA. METHODS: Coffee consumption was studied, firstly, for its association with RF (sensitised sheep cell agglutination titre >/=128) in a cross sectional survey of 6809 subjects with no clinical arthritis, and secondly, for its prediction of RA in a cohort of 18 981 men and women who had neither arthritis nor a history of it at the baseline examination in 1973-76. Up to late 1989, 126 subjects of the cohort study had developed RA, of whom, 89 were positive for RF by the time of diagnosis. RESULTS: In the cross sectional survey the number of cups of coffee drunk daily was directly proportional to the prevalence of RF positivity. Adjusted for age and sex this association was significant (p value for linear trend, 0.008), but after further adjustment for smoking the linear trend declined below significance (p=0.06). In the cohort study there was an association between coffee consumption and the risk of RF positive RA that was not due to age, sex, level of education, smoking, alcohol intake, body mass index, or serum cholesterol. After adjustment for these potential confounders the users of four or more cups a day still had a relative risk of 2.20 (95% confidence interval 1.13 to 4.27) for developing RF positive RA compared with those drinking less. Coffee consumption did not predict the development of RF negative RA. CONCLUSION: Coffee consumption may be a risk factor for RA, possibly through mechanisms contributing to the production of RF. This hypothesis remains to be tested in further studies.

Adult↗
PubMed2000

Serum C-reactive protein does not predict rheumatoid arthritis.

OBJECTIVE: Clinical rheumatoid arthritis (RA) is preceded by an immunological process. Our objective was to investigate C-reactive protein (CRP) for its prediction of RA. METHODS: A case-control study was nested within a Finnish cohort of 19,072 adults who had no arthritis and no history of the disease at the baseline examination conducted between 1973 and 1977. By late 1989, 124 had developed RA. Three controls for each incident case were individually matched for sex, age, and municipality. The CRP concentration was measured by a sensitive ELISA. RESULTS: No difference was noted in serum CRP levels between cases and controls. The odds ratios (95% confidence intervals) of RA in the quintiles of CRP were 1.0, 0.89 (0.45-1.76), 1.11 (0.59-2.08), 0.99 (0.51-1.91), and 0.95 (0.49-1.87). Similarly, there was no difference when the data were analyzed in strata of sex, age, rheumatoid factor (RF) status at baseline, and length of time from taking the specimens to the onset of clinical disease. CONCLUSION: Pre-rheumatoid immunological process as reflected in RF production is not associated with any marked inflammation or tissue injury heightening CRP.

Adult↗
PubMed2000

Antifilaggrin antibodies within "normal" range predict rheumatoid arthritis in a linear fashion.

OBJECTIVE: Increasing attention has been paid to the significance of antifilaggrin antibodies (AFA) in rheumatoid arthritis (RA). We studied the prediction of RA by AFA in serum specimens from the period prior to the onset of clinical RA. METHODS: A case-control study was nested within a Finnish cohort of 19.072 adults who had neither arthritis nor a history of it at the baseline examination during 1973-77. Pre-illness serum specimens for the assay of AFA by ELISA, using filaggrin purified from human skin as the antigen, were available from 124 of the 126 patients who had developed RA by late 1989. Of the incident cases 89 were positive for rheumatoid factor (RF). Three controls per each incident case were individually matched for sex, age, and municipality. RESULTS: Pre-illness serum AFA level was found to be directly proportional to the risk of RF positive RA. The odds ratio (95% confidence interval) in the highest quintile compared to the lowest quintile was 5.4 (2.2-13.6). In the subgroup of subjects positive for RF at baseline the figure was 24 (4.0-140). AFA did not predict the development of RF negative RA. A close association of the same order of magnitude between RF and AFA was noted in the pre-illness sera and in the control sera. CONCLUSION: AFA still within the "normal" range predicts RA in a linear fashion. AFA and RF are associated markers of the rheumatoid immunological process.

Adult↗
PubMed1999

Serum testosterone and sex hormone-binding globulin concentrations and the risk of prostate carcinoma: a longitudinal study.

BACKGROUND: It has been hypothesized that high androgen levels are determinants of prostate carcinoma. METHODS: Serum concentrations of testosterone, sex hormone-binding globulin (SHBG), and androstenedione were analyzed to determine their role as predictors of prostate carcinoma in a longitudinal, population-based, nested case-control study. The serum concentrations of testosterone, SHBG, and androstenedione were determined from serum samples collected by the Finnish Mobile Clinic Health Examination Survey between 1968-1972 and stored at -20 degrees C. During a follow-up period of 24 years, a total of 166 prostate carcinoma cases occurred among men who originally were cancer free. Two controls (matched for age and municipality) were chosen. RESULTS: There was no association between serum testosterone, SHBG, or androstenedione concentrations and the occurrence of subsequent prostate carcinoma in the total study population or in subgroups determined based on age or body mass index. The association was not strengthened by simultaneous adjustment for the hormonal variables. CONCLUSIONS: The results of the current study do not appear to corroborate the hypothesis that serum testosterone, SHBG, or androstenedione are determinants of the subsequent occurrence of prostate carcinoma.

Aged↗
PubMed1999

Risk of colorectal and other gastro-intestinal cancers after exposure to nitrate, nitrite and N-nitroso compounds: a follow-up study.

N-nitroso compounds are potent carcinogens detected in foodstuffs. The importance of dietary nitrosamines in relation to human cancer development is, however, uncertain. We studied the relationship between intake of nitrates, nitrites and N-nitrosodimethylamine (NDMA) and risk of cancers of the gastro-intestinal tract in a cohort of 9,985 adult Finnish men and women. During a follow-up period of up to 24 years, 189 gastro-intestinal cancer cases were diagnosed in the cohort, initially free from cancer. Intake of nitrate, nitrite and NDMA were estimated, based on food-consumption data from a 1-year dietary history interview covering the total diet of the participants. A significant positive association was observed between intake of NDMA and subsequent occurrence of colorectal cancer with a relative risk (RR) between the highest and lowest quartiles of intake of 2.12 [95% confidence interval (CI) 1.04-4.33]. Of various sources of N-nitroso compounds, intake of smoked and salted fish was significantly (RR = 2.58, 95% CI 1.21-5.51) and intake of cured meat was non-significantly (RR = 1.84, 95% CI 0.98-3.47) associated with risk of colorectal cancer. No similar association was observed for intake of other fish or other meat. No significant associations were observed between NDMA intake and cancers of the head and neck combined or of the stomach or between nitrate or nitrite intake and risk of cancers of the gastro-intestinal tract. Our results are in line with the idea that N-nitroso compounds can induce colorectal cancer in humans.

Adolescent↗
PubMed1999

Reliability of perceived health by sex and age.

The aim of this study was to assess the test-retest reliability of a measure of perceived general health by sex and age. The study analyzed data from the nationally representative Mini-Finland Health Survey of 8000 adults aged 30 and over. The subjects were invited to attend a personal health interview and a health examination in 1978-1980. Altogether 7217 persons participated. Perceived general health was measured at the personal health interview and in the self-administered questionnaire 1-6 weeks apart. The identical questions were: how would you assess your current health? The response alternatives were good, fairly good, intermediate, fairly poor, poor and cannot say. This study showed that among men and women unweighted agreement of the 'good-intermediate-poor' categorization of perceived health was around 70% and unweighted kappa-values were around 0.5. Only in the oldest age-group (75+) reliability declined below these levels. The fair or good reliability of perceived health observed in this study gives additional confidence for using this general measure of overall health status in future research.

Adult↗
PubMed1999

Low vitamin E status is a potential risk factor for insulin-dependent diabetes mellitus.

OBJECTIVES: To study the association of vitamin E status with occurrence of insulin-dependent diabetes mellitus (IDDM). DESIGN: A case-control study nested within a 21-year follow-up study. SUBJECTS: Nineteen incident IDDM patients with an average age of 28 years and three individually matched controls per patient. MAIN OUTCOME MEASURE: Serum concentrations of alpha-tocopherol. RESULTS: Serum alpha-tocopherol concentration at the baseline examination was inversely associated with IDDM occurring 4-14 years later. The cholesterol-adjusted relative risk of IDDM between the highest and lowest thirds of the vitamin concentration was 0.12 (95% confidence interval = 0.02-0.85). CONCLUSIONS: The finding corroborates the hypothesis of a protective effect of vitamin E against development of IDDM. Because of the relatively old age of the patients in the present population, further epidemiological studies on the topic are warranted.

Adult↗
PubMed1999

Shoulder joint impairment among Finns aged 30 years or over: prevalence, risk factors and co-morbidity.

OBJECTIVES: To describe the prevalence, risk factors and consequences of shoulder joint impairment in the population. METHODS: A representative sample (n = 7217) of the Finnish population aged > or = 30 yr participated in a health examination survey (the Mini-Finland Health Survey). The design of the survey allowed an independent assessment of disability, reported shoulder pain, shoulder joint impairment and major chronic co-morbidity. RESULTS: Shoulder impairment was observed in 8.8%, while pain was reported by 30%. The prevalence of shoulder pain decreased among the elderly, whereas impairments increased up to 20% of those aged 75-80 yr. In addition to age, sex, previous injury to the shoulder joint and a history of physically heavy work, diabetes was associated with shoulder impairment (OR 1.6, 95% CI 1.2-2.1). Shoulder impairment was associated with disability (adjusted OR 2.0, CI 1.6-2.5). CONCLUSIONS: Shoulder impairment is an important component of ill health among the elderly, and cannot be reduced to reported pain alone.

Adult↗