Biomedical subjects

Paul Knekt

Publications and source records attributed to Paul Knekt.

At least 19 recordsLinked to original sources

PubMed2007

Surgical or nonoperative treatment for lumbar spinal stenosis? A randomized controlled trial.

STUDY DESIGN: A randomized controlled trial. OBJECTIVES: To assess the effectiveness of decompressive surgery as compared with nonoperative measures in the treatment of patients with lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: No previous randomized trial has assessed the effectiveness of surgery in comparison with conservative treatment for spinal stenosis. METHODS: Four university hospitals agreed on the classification of the disease, inclusion and exclusion criteria, radiographic routines, surgical principles, nonoperative treatment options, and follow-up protocols. A total of 94 patients were randomized into a surgical or nonoperative treatment group: 50 and 44 patients, respectively. Surgery comprised undercutting laminectomy of the stenotic segments in 10 patients augmented with transpedicular fusion. The primary outcome was based on assessment of functional disability using the Oswestry Disability Index (scale, 0-100). Data on the intensity of leg and back pain (scales, 0-10), as well as self-reported and measured walking ability were compiled at randomization and at follow-up examinations at 6, 12, and 24 months. RESULTS: Both treatment groups showed improvement during follow-up. At 1 year, the mean difference in favor of surgery was 11.3 in disability (95% confidence interval [CI], 4.3-18.4), 1.7 in leg pain (95% CI, 0.4-3.0), and 2.3(95% CI, 1.1-3.6) in back pain. At the 2-year follow-up, the mean differences were slightly less: 7.8 in disability (95% CI, 0.8-14.9) 1.5 in leg pain (95% CI, 0.3-2.8), and 2.1 in back pain (95% CI, 1.0-3.3). Walking ability, either reported or measured, did not differ between the two treatment groups. CONCLUSIONS: Although patients improved over the 2-year follow-up regardless of initial treatment, those undergoing decompressive surgery reported greater improvement regarding leg pain, back pain, and overall disability. The relative benefit of initial surgical treatment diminished over time, but outcomes of surgery remained favorable at 2 years. Longer follow-up is needed to determine if these differences persist.

Aged↗

PubMed2006

Helicobacter pylori IgA and IgG antibodies, serum pepsinogen I and the risk of gastric cancer: changes in the risk with extended follow-up period.

The prediction of Helicobacter pylori antibodies immunoglobulin A (IgA) and immunoglobulin G (IgG) and serum pepsinogen I (PG I) on gastric cancer occurrence was studied in a nested case-control study, based on 225 incident cancer cases and 435 matched controls from a Finnish cohort followed from 1966-1991. The odds ratio of noncardia gastric cancer between infected and noninfected persons was 3.12 (95% confidence interval (CI)=1.97-4.95) for elevated IgA and 2.88 (CI: 1.63-5.07) for elevated IgG antibodies. The odds ratio between low and high PG I was 2.24 (CI: 1.43-3.49). The strength of association was significant for IgA antibodies during the total follow-up, but for IgG antibodies this was only true for follow-up periods of 15 years or more. IgA antibodies were significantly associated with all registered histological subtypes apart from intestinal type adenocarcinoma. The highest gastric cancer risk was found among individuals with simultaneously elevated IgA and IgG antibodies and low PG I with an odds ratio of 10.9 (CI: 4.31-27.7) in comparison with those who were negative for both antibodies and had normal PG I. Elevated IgA and IgG antibodies and low PG I were not associated with cancers of the gastric cardia. The findings support the hypothesis that H. pylori infection is a cause of noncardia gastric cancer. Although elevated H. pylori IgA and IgG antibodies and low PG I independently could predict the occurrence of noncardia gastric cancer, their power to do so varied with the stage and length of the follow-up period and it increased when they were applied in combination.

Aged↗

PubMed2006

Validity of a food frequency questionnaire varied by age and body mass index.

BACKGROUND AND OBJECTIVE: The validity of food frequency questionnaires (FFQs) in measuring food consumption and nutrient intake has to be assessed. The objective of this study was to assess the validity of a 128-item FFQ in specific subgroups of Finnish adults. METHODS: The study included 294 subjects (137 men and 157 women). A 3-day food record was used as the reference method. RESULTS: The mean intake of all nutrients except alcohol was higher measured with the FFQ than with the food records. In general, the Pearson correlations for energy adjusted nutrients between the FFQ and the food records were higher in women than in men. The correlations ranged from 0.14 (retinol) to 0.66 (fiber and alcohol) in men, and from 0.20 (long-chain n-3 fatty acids) to 0.70 (alcohol) in women. The results in subgroups showed that measuring nutrient intakes is more difficult among younger (30-50 years) women and overweight men and women than among others. CONCLUSIONS: The study showed that the FFQ is a useful tool in epidemiologic studies in measuring the diet of Finnish adults given that the problems among specific subgroups are taken into account in interpretation.

Adult↗

PubMed2006

Intake of fish and long-chain n-3 fatty acids and the risk of coronary heart mortality in men and women.

This prospective study investigated the relationship between the consumption of fish and intake of long-chain n-3 fatty acids and the risk of coronary heart mortality in 2775 men and 2445 women aged from 30 to 79 years who were free of CHD and had participated in a health examination survey from 1967 to 1972. In total, 335 men and 163 women died of CHD during a follow-up until the end of 1992. A dietary history interview method provided data on habitual consumption of fish and other foods over the preceding year at baseline. The intakes of long-chain n-3 fatty acids were calculated on the basis of food composition values of Finnish foods. Higher consumption of fish was associated with a decreased risk of CHD among women, whereas no significant association was seen among men. The relative risk between the highest and the lowest quintile for fish consumption was 1.00 (95 % CI 0.70, 1.43; P for trend 0.83) for men and 0.59 (95 % CI 0.36, 0.99; P for trend 0.02) for women in analysis adjusting for age, energy intake, geographical area, BMI, serum cholesterol, blood pressure, smoking, occupation and diabetes; however, after adjustment for dietary confounders this association was no longer significant. The intake of n-3 fatty acids was not significantly associated with the risk of CHD in either men or women. In conclusion, our results for women are in line with the suggested protective effect of fish consumption against CHD but a similar association was not, however, found in men.

Adult↗

PubMed2006

Low metacarpal index predicts hip fracture: a prospective population study of 3,561 subjects with 15 years of follow-up.

BACKGROUND: Metacarpal index (MCI), measured from hand radiographs as the ratio between combined cortical thickness and bone diameter, has been suggested for assessment of bone mass and risk of osteoporotic fracture. We studied MCI for its ability to predict hip fractures. METHODS: Hand radiographs were taken and MCI determined in 3,561 subjects from a representative population sample of 8,000 Finns who were 30 years of age or over in 1978-80. Record linkage to the National Hospital Discharge Register identified 117 subjects who had been hospitalized for primary treatment of hip fracture by the end of 1994. RESULTS: High age, low body mass index, tall stature and smoking at baseline showed, independently of each other, significant associations with low MCI. Low MCI was a strong predictor of hip fracture. When adjusted for all potential confounding factors, the relative risk of hip fracture per decrement of MCI by one standard deviation (0.1) was 1.5 (95% CI 1.2-1.8). INTERPRETATION: Low MCI is associated with known risk factors of osteoporosis and predicts hip fracture. Since hand radiographs are easily available at low cost, measurements of MCI can be used as an alternative approach to find osteoporotic individuals with a high risk of hip fracture.

Absorptiometry, Photon↗

PubMed2006

Schizophrenia, neuroleptic medication and mortality.

BACKGROUND: There is an excess of death from natural causes among people with schizophrenia. AIMS: Schizophrenia and its treatment with neuroleptics were studied for their prediction of mortality in a representative population sample of 7217 Finns aged >/= 30 years. METHOD: A comprehensive health examination was carried out at baseline. Schizophrenia was determined using the Present State Examination and previous medical records. RESULTS: During a 17-year follow-up, 39 of the 99 people with schizophrenia died. Adjusted for age and gender, the relative mortality risk between those with schizophrenia and others was 2.84 (95% CI 2.06-3.90), and was 2.25 (95% CI1.61-3.15) after further adjusting for somatic diseases, bloodpressure, cholesterol, body mass index, smoking, exercise, alcohol intake and education. The number of neuroleptics used at the time of the baseline survey showed a graded relation to mortality. Adjusted for age, gender, somatic diseases and other potential risk factors for premature death, the relative risk was 2.50 (95% CI1.46-4.30) per increment of one neuroleptic. CONCLUSIONS: There is an urgent need to ascertain whether the high mortality in schizophrenia is attributable to the disorder itself or the antipsychotic medication.

Adult↗

PubMed2005

Association of Helicobacter pylori IgA antibodies with the risk of peptic ulcer disease and gastric cancer.

AIM: To compare the prevalence of Helicobacter pylori (H pylori) IgG and IgA antibodies between adult subjects, with defined gastric diseases, non-defined gastric disorders and those representing the population. METHODS: Data on H pylori IgG and IgA antibodies, determined by enzyme immunoassay, were analyzed in 3,252 subjects with DGD including 482 patients with gastric ulcer, 882 patients with duodenal ulcer, 1,525 patients with chronic gastritis only and 363 subjects with subsequent gastric cancer, 19,145 patients with NoDg and 4,854 POPUL subjects. The age-adjusted prevalences were calculated for 1- and 20-year age cohorts. RESULTS: The prevalences of IgG antibodies were equally high (89-96%) in all 20-year age cohorts of the DGD groups, whereas the prevalences of IgG antibodies were lower and increased by age in the POPUL and NoDg groups. The prevalences of IgA antibodies were also higher in the DGD groups; among them CA (84-89%) and GU groups (78-91%) showed significantly higher prevalences than DU (68-77%) and CG patients (59-74%) (OR 2.49, 95%CI 1.86-3.34 between the GU and DU groups). In the CA, GU, and DU groups, the IgA prevalences showed only minor variation according to age, while they increased by age in the CG, POPUL, and NoDg groups (P<=0.0001). The IgA response, but not the IgG response, was associated with an increased risk of CA (OR 2.41, 95%CI 1.79-3.53) and GU (OR 2.57, 95%CI 1.95-3.39) in comparison with CG patients. CONCLUSION: An IgA antibody response during H pylori infection is significantly more common in CA and GU patients as compared with CG patients.

Adult↗

PubMed2005

No serological evidence of association between prostate cancer and infection with herpes simplex virus type 2 or human herpesvirus type 8: a nested case-control study.

Sexual history has consistently been found to be a risk factor for the development of prostate cancer. An association between prostate cancer and herpes simplex virus type 2 (HSV-2) or Kaposi sarcoma-associated herpesvirus/human herpesvirus type 8 (HHV-8) infections has also been reported. Linkage of data on a cohort of 20,243 healthy Finnish men identified 165 cases of prostate cancer that were diagnosed up to 24 years after donation of a serum sample. Two control subjects were matched by age, sex, and municipality of residence to each case patient. Serum levels of immunoglobulin G against HSV-2 and HHV-8 were determined. Neither HSV-2 infection (odds ratio [OR], 0.93 [95% confidence interval {CI}, 0.44-1.96]) nor HHV-8 infection (OR, 0.74 [95% CI, 0.19-2.88]) was associated with prostate cancer.

Adolescent↗

PubMed2005

Dietary patterns and the incidence of type 2 diabetes.

Major dietary patterns were studied for the ability to predict type 2 diabetes mellitus in a cohort of 4,304 Finnish men and women aged 40-69 years and free of diabetes at baseline in 1967-1972. Factor analysis was used to identify dietary patterns from dietary data that were collected using a 1-year dietary history interview. A total of 383 incident cases of type 2 diabetes occurred during a 23-year follow-up. Two major dietary patterns were identified. The pattern labeled "prudent" was characterized by higher consumption of fruits and vegetables, and the pattern labeled "conservative" was characterized by consumption of butter, potatoes, and whole milk. The relative risks (adjusted for nondietary confounders) between the extreme quartiles of the pattern scores were 0.72 (95% confidence interval: 0.53, 0.97; p(trend) = 0.03) for the prudent pattern and 1.49 (95% confidence interval: 1.11, 2.00; p(trend) = 0.01) for the conservative pattern. Thus, the prudent dietary pattern score was associated with a reduced risk and the conservative pattern score was associated with an increased risk of type 2 diabetes. In light of these results, it appears conceivable that the risk of developing type 2 diabetes can be reduced by changing dietary patterns.

Adult↗

PubMed2004

Obesity and unhealthy life-years in adult Finns: an empirical approach.

BACKGROUND: Obesity is more strongly related to morbidity and disability than to mortality. Obese individuals are thus expected to have more unhealthy life-years than normal-weight persons. The objective of the present study was to quantify the number of excess unhealthy life-years in obese individuals. METHODS: A representative cohort of 19 518 Finnish men and women aged 20 to 92 years was followed for 15 years. Participation rate was 83%. Obesity was defined as a body mass index of 30.0 or higher. The number of unhealthy life-years due to premature work disability, hospitalization for coronary heart disease, and need for long-term medication was calculated per category of body mass index. RESULTS: During the follow-up of 15 years, obese men who never smoked aged 20 to 64 years had, on average, 0.63 more years of work disability, 0.36 more years of coronary heart disease, and 1.68 more years of longterm medication use, than normal-weight counterparts. Obese women had, respectively, 0.52, 0.46, and 1.49 more years from these conditions than normal weight women. The excess risks of morbidity and disability due to obesity were highest in the youngest age groups and exceeded those of mortality in all age groups. Obese men and women 65 years and older who never smoked had, respectively, 1.71 and 1.41 excess unhealthy life-years (not statistically significant) due to premature need for long-term medication compared with normal-weight subjects, but no excess unhealthy life-years due to coronary heart disease. CONCLUSIONS: Obesity has a lifetime impact on disability and morbidity. A further increase in obesity will lead to an increase in unhealthy life-years and in direct and indirect health care costs.

Adult↗

PubMed2004

Antibodies to periodontal pathogens and stroke risk.

BACKGROUND AND PURPOSE: The association between cerebrovascular events and periodontitis has been found in few studies based on clinical periodontal examinations. However, evidence on the association between periodontal pathogens and stroke is lacking. Therefore, the aim of the study was to investigate whether elevated levels of serum antibodies to major periodontal pathogens predict stroke in a case-control study. METHODS: The study population comprised 6950 subjects (aged 45 to 64 years) who participated in the Mobile Clinic Health Survey in 1973 to 1976 in Finland. During a follow-up of 13 years, a total of 173 subjects had a stroke. From these, 64 subjects had already experienced a stroke or had signs of coronary heart disease (CHD) at baseline, whereas 109 subjects were apparently healthy. Two controls per case were matched for age, gender, municipality, and disease status. Serum IgG and IgA class antibody levels to the periodontal pathogens, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis, were determined by multiserotype enzyme-linked immunosorbent assay. RESULTS: The cases identified during the follow-up that were free of stroke or CHD at baseline were more often IgA-seropositive for A. actinomycetemcomitans than were their controls, 41.3% versus 29.3%. Compared with the seronegative, the seropositive subjects had a multivariate odds ratio of 1.6 (95% CI, 1.0 to 2.6) for stroke. The patients with a history of stroke or CHD at baseline were more often IgA-seropositive for P. gingivalis than were their controls, 79.7% versus 70.2%. When compared with the seronegative, the seropositive subjects had an odds ratio of 2.6 (1.0 to 7.0) for secondary stroke. CONCLUSIONS: The present prospective study provides serological evidence that an infection caused by major periodontal pathogens is associated with future stroke.

Aggregatibacter actinomycetemcomitans↗

PubMed2004

Dietary fiber and risk of coronary heart disease: a pooled analysis of cohort studies.

BACKGROUND: Few epidemiologic studies of dietary fiber intake and risk of coronary heart disease have compared fiber types (cereal, fruit, and vegetable) or included sex-specific results. The purpose of this study was to conduct a pooled analysis of dietary fiber and its subtypes and risk of coronary heart disease. METHODS: We analyzed the original data from 10 prospective cohort studies from the United States and Europe to estimate the association between dietary fiber intake and the risk of coronary heart disease. RESULTS: Over 6 to 10 years of follow-up, 5249 incident total coronary cases and 2011 coronary deaths occurred among 91058 men and 245186 women. After adjustment for demographics, body mass index, and lifestyle factors, each 10-g/d increment of energy-adjusted and measurement error-corrected total dietary fiber was associated with a 14% (relative risk [RR], 0.86; 95% confidence interval [CI], 0.78-0.96) decrease in risk of all coronary events and a 27% (RR, 0.73; 95% CI, 0.61-0.87) decrease in risk of coronary death. For cereal, fruit, and vegetable fiber intake (not error corrected), RRs corresponding to 10-g/d increments were 0.90 (95% CI, 0.77-1.07), 0.84 (95% CI, 0.70-0.99), and 1.00 (95% CI, 0.88-1.13), respectively, for all coronary events and 0.75 (95% CI, 0.63-0.91), 0.70 (95% CI, 0.55-0.89), and 1.00 (95% CI, 0.82-1.23), respectively, for deaths. Results were similar for men and women. CONCLUSION: Consumption of dietary fiber from cereals and fruits is inversely associated with risk of coronary heart disease.

Cohort Studies↗

PubMed2004

Secular changes in disability among middle-aged and elderly Finns with and without coronary heart disease from 1978-1980 to 2000-2001.

PURPOSE: To examine time trends in the prevalence of coronary heart disease (CHD) and disability. METHODS: Data were used from two large nationally representative cross-sectional health examination surveys conducted in Finland (1978-1980 and 2000-2001). RESULTS: The prevalence of CHD decreased in men and women aged 45 to 64 years and increased among those aged 75 years or more. In men with and without CHD, and in women without CHD, the prevalence of disability decreased until the age of 75 years, but in women with CHD no statistically significant decrease was observed. CONCLUSIONS: Favorable changes in prevalence of CHD and disability have occurred in people aged 45 to 75 years, but not in older people particularly in women. The proportion of decrease in disability attributable to CHD was estimated to be up to 25%. The causes of unequal development by age and gender should be ascertained.

Age Distribution↗

PubMed2004

Disability predicted mortality in men but not women with coronary heart disease.

OBJECTIVE: Disability increases mortality in patients with myocardial infarction in acute clinical settings, but the impact of disability on mortality in persons with coronary heart disease (CHD) at the population level is largely unknown. STUDY DESIGN AND SETTING: We assessed disability as a predictor of mortality among 4,501 men and women aged 45 and over in a national sample of the Finnish population, examined in 1978-1980. RESULTS: During follow-up until the end of 1994, 897 men and 846 women died. Disability was related to increased all-cause and CHD mortality after adjustment for cardiovascular risk factors in men regardless of baseline CHD status. In women with CHD at baseline, disability was not related to excess mortality, although disability predicted mortality in women without baseline CHD. CONCLUSION: Disability predicts mortality in men with CHD, but not in women. This may reflect a gender difference in the nature of CHD, but these findings need to be verified in other large-scale population studies.

Age Factors↗

PubMed2004

Impact of cardiovascular diseases on activity limitations and need for help among older persons.

BACKGROUND AND OBJECTIVE: The aim of this study was to estimate the importance of specific chronic cardiovascular diseases (CVDs) as determinants of disability. METHODS: One thousand two hundred eighty-eight (86%) participants from a random population sample of 1,500 individuals (from two geographical regions of Finland) aged 65-74 years were interviewed and clinically examined in 1997. RESULTS: CVDs were strongly associated with disability. However, mental disorders were the strongest determinant of disability. Of specific CVDs, cerebrovascular diseases in men, and myocardial infarction, heart failure, and cerebrovascular diseases in women were significantly associated with disability after adjustment for age and comorbidity. In men 33% and in women 24% of disability was attributable to CVD, excluding lone hypertension. CONCLUSION: CVDs are important determinants of disability among Finns aged 65-74 years. Due to the growing number of elderly people with CVDs, disability associated with these diseases is likely to become a growing social and health burden to the community.

Activities of Daily Living↗

PubMed2004

Blood biochemistry and the risk of cancer.

A longitudinal study based on a serum sample bank was carried out in Finland to find out the association between biochemical substances and the subsequent risk of cancer. The objective was to evaluate the consistency between means of individually estimated levels of these compounds and levels based on pooling. Levels of alpha-tocopherol, beta-carotene, retinol, retinol-binding protein, and ceruloplasmin were estimated by primary site and sex and partly by age and morphology. The concentrations in pooled samples were consistently lower than the averages of the individual samples. On the basis of individual samples, all the five biochemical compounds had a rather consistent protective effect on the risk of cancers at most primary sites. This protective effect disappeared in the pool analyses, and more than half of exposure contrasts showed an opposite sign. For ceruloplasmin, the effect of pooling was smaller but not negligible. The results of this study emphasize the demand to standardize the collecting, handling, and analysing of samples in serum banks. They are, furthermore, consistent with the hypothesis that pooling of biochemical samples affects the levels of the substances and may affect the conclusions of epidemiological studies on causes of diseases.

Biomarkers, Tumor↗

PubMed2004

Antioxidant vitamins and coronary heart disease risk: a pooled analysis of 9 cohorts.

BACKGROUND: Epidemiologic studies have suggested a lower risk of coronary heart disease (CHD) at higher intakes of fruit, vegetables, and whole grain. Whether this association is due to antioxidant vitamins or some other factors remains unclear. OBJECTIVE: We studied the relation between the intake of antioxidant vitamins and CHD risk. DESIGN: A cohort study pooling 9 prospective studies that included information on intakes of vitamin E, carotenoids, and vitamin C and that met specific criteria was carried out. During a 10-y follow-up, 4647 major incident CHD events occurred in 293 172 subjects who were free of CHD at baseline. RESULTS: Dietary intake of antioxidant vitamins was only weakly related to a reduced CHD risk after adjustment for potential nondietary and dietary confounding factors. Compared with subjects in the lowest dietary intake quintiles for vitamins E and C, those in the highest intake quintiles had relative risks of CHD incidence of 0.84 (95% CI: 0.71, 1.00; P=0.17) and 1.23 (1.04, 1.45; P=0.07), respectively, and the relative risks for subjects in the highest intake quintiles for the various carotenoids varied from 0.90 to 0.99. Subjects with higher supplemental vitamin C intake had a lower CHD incidence. Compared with subjects who did not take supplemental vitamin C, those who took >700 mg supplemental vitamin C/d had a relative risk of CHD incidence of 0.75 (0.60, 0.93; P for trend <0.001). Supplemental vitamin E intake was not significantly related to reduced CHD risk. CONCLUSIONS: The results suggest a reduced incidence of major CHD events at high supplemental vitamin C intakes. The risk reductions at high vitamin E or carotenoid intakes appear small.

Adult↗

PubMed2004

Osteoarthritis in the carpometacarpal joint of the thumb. Prevalence and associations with disability and mortality.

BACKGROUND: This study was designed to investigate the prevalence of osteoarthritis in the carpometacarpal joint of the thumb in adults thirty years of age or older in Finland. METHODS: Between 1978 and 1980, a representative population sample of 8000 Finns thirty years of age or older were invited to have a comprehensive health examination; 90% accepted. Hand radiographs were made of 3595 subjects. Since the examination, the subjects have been followed systematically to assess work disability and mortality by reviewing registers covering the whole population. RESULTS: The age-adjusted prevalence of thumb carpometacarpal osteoarthritis of Kellgren grade 2, 3, or 4 was 7% for men and 15% for women. After adjustment for age, sex, and other alleged risk factors, body mass index was found to be directly proportional to the prevalence of thumb carpometacarpal osteoarthritis in both sexes. The adjusted odds ratio was 1.29 (95% confidence interval, 1.15 to 1.43) per 5-kg/m(2) increment in body mass index. No significant association was found between the physical workload history and thumb carpometacarpal osteoarthritis. Restricted mobility of the thumb and local tenderness and swelling were frequently found in conjunction with radiographic evidence of thumb carpometacarpal osteoarthritis. Advanced (grade-3 or 4) thumb carpometacarpal osteoarthritis predicted the total mortality rate in men (adjusted relative risk, 1.32; 95% confidence interval, 1.03 to 1.69). Radiographic signs of thumb carpometacarpal osteoarthritis did not predict work disability. CONCLUSIONS: and CLINICAL RELEVANCE: Obesity is a strong determinant of thumb carpometacarpal osteoarthritis in both sexes. The effect of thumb carpometacarpal osteoarthritis on disability and mortality in the general population is modest. Because of the rarity of ensuing disability, carpometacarpal osteoarthritis of the thumb is likely to be underdiagnosed in clinical practice.

Adult↗