Biomedical subjects

Hilkka Riihimäki

Publications and source records attributed to Hilkka Riihimäki.

At least 19 recordsLinked to original sources

PubMed2006

Co-occurrence of musculoskeletal pain among female kitchen workers.

OBJECTIVES: The co-occurrence of musculoskeletal pain symptoms in seven body sites and their combinations among women in kitchen work were studied. METHODS: Data on musculoskeletal pain during the past 3 months in the neck, shoulders, forearms/hands, low back, hips, knees and ankles/feet were gathered by questionnaire from 495 female workers (mean age 45 years) in connection with an ergonomic intervention study in municipal kitchens of four cities in Finland. Altogether 122 kitchens (60% of those eligible) participated in the study. The response rate in the participating kitchens was 98%. RESULTS: The 3-month prevalence of any musculoskeletal pain was 87%, the most common sites being the neck (71%), low back (50%) and forearms/hands (49%). About 73% of the subjects had pain in at least two, 36% in four or more, and 10% in 6-7 sites. In pair wise comparisons, e.g. neck pain was associated with pain in other sites with prevalence ratios (PR) varying from 1.3 to 1.6, and ankle or foot pain with ratios between 1.9 and 2.4. The seven pain symptoms occurred in more than 80 different combinations. When the co-occurrence of pain was studied in three larger anatomical areas, i.e. any pain in the axial (neck and low back), upper limb and lower limb areas, subjects reporting concurrent pain in all three were the largest category (36% of the respondents). Altogether 53% of the workers reported pain in at least the axial and upper limb areas, and 48% in at least the axial and lower limb areas. CONCLUSIONS: Widespread co-occurrence of musculoskeletal pain symptoms was common among female kitchen workers with slight predominance in the upper body.

Adult↗

PubMed2006

Serum lipids and low back pain: an association? A follow-up study of a working population sample.

STUDY DESIGN: Cohort study with 5-, 10-, and 28-year follow-up. OBJECTIVES: To examine associations between baseline serum lipid concentrations and later low back pain (LBP). SUMMARY OF BACKGROUND DATA: Atherosclerosis of the lumbar vessels has been suggested as a mechanism leading to disc degeneration and LBP. Cholesterol is considered essential for atherosclerosis development. METHODS: A sample (n = 902) of employees in an engineering company was examined for serum total cholesterol and triglycerides, body mass index (BMI), smoking, exercise, work history, and LBP in 1973. By November 2000, 232 subjects had died. In 1978, 748 (84% of the survivors), in 1983, 654 (76%), and in 2000, 546 (81%) responded to a follow-up questionnaire. RESULTS: In men, baseline serum total cholesterol predicted new cases of radiating LBP in the 5-year follow-up (highest tertile vs. lowest: odds ratio [OR], 2.5; 95% confidence interval [CI], 1.1-5.9) and in the 10-year follow-up (OR, 2.8; 95% CI, 1.3-6.1), adjusted for age, occupational class, work history, BMI, smoking and exercise. Also, serum triglycerides predicted new cases in the latter examination (OR, 2.6; 95% CI, 1.2-5.8). In women, no associations were seen until the 10-year follow-up, when their results were similar to those in men. In the total material, serum total cholesterol predicted radiating LBP reported both at the 10- and the 28-year follow-up. CONCLUSIONS: High serum lipids predicted incident radiating LBP, consistent with the atherosclerosis-LBP hypothesis.

Adult↗

PubMed2006

Sleep disturbances as predictors of hospitalization for back disorders-a 28-year follow-up of industrial employees.

STUDY DESIGN: A prospective cohort study. OBJECTIVE: To study the relationship of sleep disturbances with severe back disorders leading to hospitalization. SUMMARY OF BACKGROUND DATA: Sleep disturbances are associated with persistent pain syndromes, but little is known about their relationship with back disorders. METHODS: The first hospital admission for back disorders from 1973 to 2000 was studied in a cohort of metal industry workers (n = 902). The occurrence of sleep disturbances at baseline was categorized as: none; 1 type (either difficulties in falling asleep/waking up at night or nightmares); or both types. Cox proportional hazards regression was used to estimate the time between the assessment of risk factors and first hospital admission for back disorders. RESULTS: Those individuals who had 1 type of sleep disturbance had a 2.1-fold (95% confidence interval 1.1-3.8) risk of back-related hospitalization, and those with both types of disturbance a 2.4-fold (1.2-4.6) risk, compared with those with no sleep disturbances. The hazard ratios were 2.1; 1.0-4.6 and 2.9; 1.2-7.1, respectively, when patients with chronic back disease or recurrent back symptoms at baseline were excluded from the analyses. CONCLUSION: These findings suggest that sleep disturbances are predictive of hospitalization for back disorders. The mechanism underlying this association warrants further study.

Aged↗

PubMed2006

Vitamin D receptor gene polymorphisms and susceptibility of hand osteoarthritis in Finnish women.

We examined whether polymorphisms of the vitamin D receptor (VDR) gene was associated with individual risk of hand osteoarthritis (OA). Radiographs of both hands of 295 dentists and of 248 teachers were examined and classified for the presence of OA using reference images. The VDR ApaI and TaqI genotypes were determined by PCR-based methods. No association was observed between the VDR polymorphisms and the odds of overall hand OA. However, the carriers of the VDR t allele or At haplotype were at almost half the odds of symmetrical hand OA (odds ratio [OR] = 0.60, 95% confidence interval [CI] = 0.38-0.94 and OR = 0.59, 95% CI = 0.38-0.93, respectively) compared with the carriers of the T allele and of the non-At haplotype, respectively. Increased odds of this disease, on the contrary, was observed for women with two copies of the VDR a allele (OR = 1.93, 95% CI = 1.99-3.70) compared with women with the AA genotype. Conversely, the VDR a allele carriage was associated with a tendency of lowered odds of osteophyte (OR = 0.51, 95% CI = 0.25-1.03). When the genotype data were used to construct haplotypes, the VDR AaTt joint genotype appeared to pose a remarkably lower odds (OR = 0.26, 95% CI = 0.08-0.91) of osteophyte compared with the AAtt joint genotype. As a novel finding we observed a joint effect of a low calcium intake and VDR polymorphisms on symmetrical OA; the OR was 2.64 (95% CI = 1.29-5.40) for carriers of the aT haplotype with low daily calcium intake compared with non-carriers of the haplotype with high daily calcium intake. Our results suggest that VDR gene polymorphisms play a role in the etiology of symmetrical hand OA. Moreover, the association between the VDR gene and OA may be modified by calcium intake.

Female↗

PubMed2006

Cardiovascular risk factors and low-back pain in a long-term follow-up of industrial employees.

OBJECTIVES: Atherosclerosis of the lumbar vessels has been suggested as a mechanism leading to low-back pain (LBP). We studied whether seven cardiovascular disease (CVD) risk factors predict LBP. METHODS: A sample (N=902) stratified by gender, age, and occupational class was drawn from employees in an engineering company in 1973 and examined for body mass index (BMI), smoking, exercise, serum total cholesterol and triglyceride concentrations, systolic blood pressure (SBP), diastolic blood pressure (DBP), and LBP. By November 2000, 232 persons had died, 108 from cardiovascular causes. In 2000, 546 (81% of the survivors) responded to a follow-up questionnaire on, for example, LBP. RESULTS: Among the men, frequent local LBP at follow-up was predicted by high triglyceride and DBP levels and being a past smoker at baseline, adjusted for age, occupational class and frequent local LBP at baseline. In analogous models, high triglyceride and SBP levels and smoking (past and current) predicted frequent radiating LBP. An increased LBP score was predicted by a high BMI, serum total cholesterol, triglyceride, SBP and DBP levels, and smoking status at baseline. When BMI was allowed for, the associations between triglyceride level and all LBP outcomes persisted, as well as the association between SBP and frequent radiating LBP and an increased LBP score. An overall score of CVD risk factors showed a graded association with increased LBP. Among the women, a high BMI predicted frequent local and radiating LBP, and smoking at baseline predicted frequent radiating LBP and an increased LBP score. CONCLUSIONS: The study adds to the evidence supporting the atherosclerosis-LBP hypothesis particularly for men.

Aged↗

PubMed2005

Persistence of low back pain reporting among a cohort of employees in a metal corporation: a study with 5-, 10-, and 28-year follow-ups.

Low back pain (LBP) is a common symptom among adults but little is known about its persistence over time in defined populations. The aim of this study was to examine the persistence of LBP among a cohort of industrial employees studied in four successive surveys during a total of 28 years. Cross-tabulations and logistic regression was used to estimate the interdependence of LBP occurrence at the surveys. At baseline, 54% of the subjects reported local LBP and 25% LBP radiating to the lower limb(s). Persistent or recurrent LBP was common. Of those with LBP at baseline, 75, 73, and 88% reported it also at the 5-, 10- or 28-year follow-up, respectively. Of those with radiating pain, 66, 65, and 69% were symptomatic 5, 10, or 28 years later. The onset of reporting LBP increased during follow-up. Of those without local LBP at baseline, 33, 37 and 64% had pain at the 5-, 10-, or 28-year follow-up, respectively. Of those without radiating LBP, 17, 22, and 46% had pain at the 5-, 10-, or 28-year follow-up. The odds ratio of local LBP at the 5-, 10-, or 28-year follow-up for those with such pain at baseline vs. not were 6.0 (95% CI 4.3-8.3), 4.7 (3.3-6.6) and 4.0 (2.6-6.3), adjusted for age, gender and occupational class. The respective figures for radiating LBP were 8.5 (5.7-12.5), 6.7 (4.4-10.1) and 2.3 (1.5-3.6). We conclude that LBP is commonly recurrent.

Age Distribution↗

PubMed2005

Low back pain among nurses: a follow-up beginning at entry to the nursing school.

STUDY DESIGN: A prospective cohort. OBJECTIVES: To investigate the prevalence of back pain from entering the nursing school through 5 years in nursing and the determinants and modifiers of back pain and disability. SUMMARY OF BACKGROUND DATA: Physical loading, psychologic characteristics, and several other factors have been associated with back pain at work in earlier studies. Because of the lack of the prework entry morbidity data, the nature of the associations between these exposures and the symptoms is unclear. That previous back pain is a predictor of later pain underlines the importance to have pre-employment data in investigations of the role of exposures at work. METHODS: Female nursing students (n = 174) were followed for 7.5 years. Data on constitutional and behavioral factors, occupational exposures, and back-related symptoms and disability were collected. Back pain was grouped into "sciatic," "sudden," or "other" and related disability. RESULTS: The lifetime cumulative prevalence of back pain increased from 31% at entry to nursing school to 72% at the end of the school and further to 82% after 5 years as a nurse. The 1-year prevalence of any back pain was 54% for the first year in nursing school, 57% for the first year as a nurse, and 64% for the fifth year as a nurse. In multivariate analyses, other back pain and related disability as a nurse were associated with back pain history at the entry to nursing school (odds ratio, 7.1; 95% confidence interval, 1.5-34; and 3.6; 1.2-11, respectively), and working in twisted/bent positions (odds ratio, 6.2; 95% confidence interval, 1.7-23; and 7.5; 2.9-20, respectively). Sudden back pain was not associated with any of the studied risk factors. Sciatic back pain was associated only with working positions (odds ratio, 6.9; 95% confidence interval, 2.1-23). CONCLUSIONS: Lifetime prevalence of back pain increased sharply during nursing school but slowly after that. Back pain at entering the nursing school was a predictor for back-related pain and disability. Self- reported occupational physical work load was associated with back pain and related disability. The nature of the association is unclear, but it is likely that back pain is exacerbated during nursing.

Adult↗

PubMed2005

Intervertebral disc degeneration in relation to the COL9A3 and the IL-1ss gene polymorphisms.

Disc degeneration is a complex condition in which environmental factors and multiple genes are expected to act together to determine the degenerative phenotype. Recently associations of COL9A2 (Trp2 allele) and COL9A3 (Trp3 allele) polymorphisms with lumbar disc disease characterized by sciatica have been reported. However, it is not known whether the Trp2 or Trp3 alleles contribute to disc degeneration (DD). In this study, the association between the collagen genes polymorphisms and lumbar DD was investigated. Furthermore, the influence of the IL-1beta(C(3954)-T) polymorphism on the association of collagen genes polymorphisms with DD was examined. Lumbar intervertebral discs of 135 middle-aged occupationally active men were evaluated with magnetic resonance imaging, using decreased signal intensity of the nucleus pulposus, disc bulges, and decreased disc height as signs of degeneration. Blood samples were analysed for the presence of COL9A3 and COL9A2 tryptophan alleles (Trp3 and Trp2 alleles). The COL11A2, COL2A1 and IL-1beta(C(3954)-T) polymorphisms were also analysed. Multivariate logistic regression analysis allowing for occupation and body mass index showed that the carriage of the Trp3 allele in the absence of the IL-1betaT(3954) allele increased the risk of dark nucleus pulposus (OR 7.0, 95% CI 1.3-38.8) and joint occurrence of degenerative changes (OR 8.0, 95% CI 1.4-44.7). There was no effect of the Trp3 allele on DD in the presence of the IL-1betaT(3954) allele. The carriers of the COL11A2 minor allele had an increased risk of disc bulges (OR 2.1, 95% CI 1.0-4.2) as compared with non-carriers. The results suggest that the effect of the COL9A3 gene polymorphism on DD might be modified by the IL-1beta gene polymorphism.

Adult↗

PubMed2005

Low back pain, work absenteeism, chronic back disorders, and clinical findings in the low back as predictors of hospitalization due to low back disorders: a 28-year follow-up of industrial employees.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To study symptoms, chronic disorders, and clinical findings in the low back, and work absenteeism, as predictors of hospitalization. SUMMARY OF BACKGROUND DATA: Socioeconomic and lifestyle factors are associated with back-related hospitalization, but the significance in the working normal population of low back symptoms and clinical findings are not known. METHODS: The cohort (n = 902) was drawn in 1973 from among employees in the metal industry (n = 2,653). The data were collected by questionnaire and a structured clinical assessment by a physiotherapist. Weight was measured. A sum score of local and radiating low back symptoms (frequency during the past year on a 4-point Likert scale) was categorized as no/yes and no/infrequent/frequent. Local and radiating symptoms were considered also separately. The data were linked with those from the Finnish Hospital Discharge Register during 1973 to 2000. Logistic regression and the Cox proportional hazard models were used. RESULTS: As compared with persons without low back pain, those with frequent or radiating low back pain had an increased risk of hospitalization due to low back disorders (hazard rate ratio (HRR), 3.0; 95% confidence interval (CI), 1.4-6.5, and 3.7; 1.8-7.7, respectively) after adjustment for age, gender, and occupational class. Similarly, clinical findings (HRR, 2.4; 95% CI, 1.3-4.7), back-related absenteeism (HRR, 3.3; 95% CI, 1.6-6.7), and chronic low back disorders (HRR, 2.8; 95% CI, 1.5-5.4) predicted hospitalization. The associations persisted when further adjusted for smoking, body mass index, and distress symptoms at baseline. CONCLUSION: Frequent or radiating low back symptoms, chronic low back disorders, back-related work absenteeism, and having clinical findings in the low back predicted inpatient hospital care for low back disorders.

Absenteeism↗

PubMed2005

Respiratory symptoms and diseases among construction painters.

OBJECTIVE: To study the self-reported prevalence of respiratory symptoms and diseases among construction painters and estimate the potential risk for this group compared with a representative group of carpenters sharing the construction work environment but without significant exposure to paint. METHODS: A questionnaire study was conducted on 1,000 male Finnish construction painters and 1,000 carpenters (mean response rate 60.5%). Symptoms and diseases of the respiratory tract were studied, by logistic regression modelling, in relation to occupation and duration of painting experience. Age, atopy and smoking habits were taken into account. RESULTS: The painters reported more asthma-like, rhinitis, laryngeal and eye symptoms than the carpenters [odds ratio (OR) 1.4-1.8]. The difference in the prevalence of asthma between the occupations was not statistically significant, but the painters with 1-10 years of painting experience had a threefold risk of asthma compared with the carpenters. Chronic bronchitis was linked to painting occupation [OR 1.9, 95% confidence interval (CI) 1.2-3.0] and to the duration of exposure; OR (CI) for over 30 years of painting was 2.2 (1.2-4.0). Occupation was not associated with allergic rhinitis or conjunctivitis. CONCLUSIONS: The results indicate a higher risk for respiratory symptoms and chronic bronchitis among construction painters than among carpenters.

Age Factors↗

PubMed2005

A population study on differences in the determinants of a specific shoulder disorder versus nonspecific shoulder pain without clinical findings.

Musculoskeletal pain frequently occurs without particular clinical findings. Pain per se may be determined by factors other than those indicating a clinical disorder. The authors examined the prevalence and determinants of clinically diagnosed chronic rotator cuff tendinitis and self-reported nonspecific shoulder pain. The Health 2000 survey, carried out in 2000-2001 in Finland, included a nationally representative sample of 8,028 persons aged 30 years or more. In the present study, analyses were restricted to subjects aged 30-64 years who had held a job during the preceding 12 months. The prevalences of chronic rotator cuff tendinitis and nonspecific shoulder pain were 2.0% (78 of 3,909 subjects) and 12% (410 of 3,525 subjects), respectively. Nonspecific pain was related to burnout (adjusted odds ratio (OR) = 1.7, 95% confidence interval (CI): 1.4, 2.2), depression (among women, the adjusted OR was 1.8 (95% CI: 1.1, 2.9) for mild depression and 3.0 (95% CI: 1.6, 5.6) for severe depression), and inability to express one's feelings (alexithymia) (adjusted OR = 1.6, 95% CI: 1.1, 2.5). However, these factors were not associated with chronic rotator cuff tendinitis, determinants of which were work-related cumulative loading on the shoulder, age, and insulin-dependent diabetes mellitus (adjusted OR = 8.8, 95% CI: 1.9, 40.3). The determinants of specific musculoskeletal disorders differ from those of subjective complaints without clinical findings. Such complaints may be indicators of adverse psychological and psychosocial factors rather than the presence of an underlying pathologic condition.

Adult↗

PubMed2004

Hand workload and the metacarpal cortical index. a study of middle-aged teachers and dentists.

We studied load-related predictors (handedness, occupation and workload history) of cortical bone mass as estimated by the metacarpal cortical index (MCI). After being randomly selected from trade-union registers, 295 female dentists and 248 teachers, aged 45-63 years (mean 54 years), participated in the study. The MCI was defined from the second metacarpal of both hands by analogue radiographs. Data regarding anthropometric measures, handedness, occupational exposure, number of pregnancies, hormonal therapy and contraceptive use, the presence of chronic diseases, dietary factors, smoking and leisure time physical activity were collected by questionnaire. Weight was measured. The dentists' workload was assessed in detail in 10-year periods. Multivariate methods were used in the statistical analysis. The metacarpal index averaged 0.62 in the right hand and 0.61 in the left hand (P = 0.02) among the right-handed subjects, while no differences by hand were observed among the left-handed or mixed-handed. The MCI of the teachers and dentists did not differ from each other, when we controlled for potential confounders. The MCI decreased similarly by age in both occupational groups. Among the dentists, workload history was inversely associated with the MCI in multivariate analyses by age group. Computer use was a positive predictor for MCI among dentists aged 55-63 years. Occupational factors seem to have contradictory effects on the MCI. Too heavy or one-sided manual work may be deleterious for cortical bone mass.

Age Factors↗

PubMed2004

Psychosocial factors at work as predictors of hospitalization for back disorders: a 28-year follow-up of industrial employees.

STUDY DESIGN: A prospective cohort study. OBJECTIVES: To study the association of psychosocial factors at work with severe back disorders leading to hospitalization. SUMMARY OF BACKGROUND DATA: Some psychosocial factors at work have been related to back pain, but little is known about their predictive role in severe back disorders. METHODS: Psychosocial factors at work were studied by questionnaire and interview in 1973 among a cohort of 902 metal industry employees. Information on hospital admissions for back disorders from the Finnish Hospital Discharge Register in 1973-2000 was linked to the data. Cox proportional hazards regression was used to estimate the time between the assessment of risk factors and the first hospital admission for intervertebral disc disorders (36 cases) and other back disorders (47 cases). RESULTS: In a model including psychosocial factors and potential confounders, low job control versus high control was associated with a 3.2-fold risk (95% confidence interval, 1.3-7.8) of hospitalization for back disorders other than those of the intervertebral disc. The corresponding rate ratio for low versus high supervisor support was 2.9 (95% confidence interval, 1.3-6.3). Job demands, coworker support, and distress were not independently associated with these disorders. The result did not change when patients with chronic back disorder at baseline were excluded from the analysis. There was no association between psychosocial factors at work and hospitalizations for intervertebral disc disorders. CONCLUSION: Low job control and low supervisor support seem to increase the risk of hospitalization for back disorders other than intervertebral disc disorders.

Adult↗

PubMed2004

Lumbosacral transitional vertebra: relation to disc degeneration and low back pain.

STUDY DESIGN: Cross-sectional magnetic-resonance imaging (MRI) study. OBJECTIVE To investigate the relation of the lumbosacral transitional vertebra to signs of disc degeneration in MRI and to low back pain (LBP). SUMMARY OF BACKGROUND DATA: An association between the transitional vertebra and herniation in the disc above has been found in patients with LBP, but knowledge of the relation to other degenerative disc changes detected in MRI and to LBP is lacking. METHODS: MR images of the lumbar spine of 138 middle-aged working men and 25 healthy young men were evaluated. The presence and type of lumbosacral transitional vertebra and of degenerative changes in intervertebral discs were evaluated. The history of low back symptoms was obtained with a questionnaire from the middle-aged men. RESULTS: The prevalence of transitional vertebra was 30%. Transitional vertebra was associated with an increased risk of degenerative changes in the disc above among the young men and with a decreased risk in the disc below among the middle-aged men. Transitional vertebra, symmetric or asymmetric, was not associated with any type of LBP in the middle-aged men. CONCLUSIONS: Lumbosacral transitional vertebra increases the risk of early degeneration in the upper disc. This effect seems to be obscured by age-related changes in the middle age. The degenerative process is slowed down in the lower disc. For these effects, the presence of a transitional vertebra should be noticed when morphologic methods are used in research on lumbosacral spine. Transitional vertebra is not associated with any type of LBP.

Adolescent↗

PubMed2004

Interleukin 1 polymorphisms and intervertebral disc degeneration.

BACKGROUND: Enzymatic breakdown of the extracellular matrix, and possibly local inflammation, contributes to intervertebral disc degeneration. We investigated whether polymorphisms within the IL-1 gene locus are associated with lumbar disc degeneration and whether the effect of occupational physical load on disc degeneration is modified by the polymorphisms. METHODS: Genotypes were determined from 133 middle-aged men who underwent magnetic resonance imaging of the lumbar spine. The participants represented 3 occupations: 40 were machine drivers, 42 carpenters, and 51 office workers. We evaluated decreased signal intensity of the nucleus pulposus, disc bulges, and decreased disc height as signs of degeneration in the L2/L3-L5/S1 discs. RESULTS: The odds ratio for disc bulges was 2.4 (95% confidence interval = 1.2-4.8) and 1.9 (1.0-3.7), in carriers of the IL-1alphaT or IL-1betaT alleles, respectively. The TT genotype of the IL-1alpha gene carried more than 3-fold risk of disc bulges as compared with the CC genotype. CONCLUSIONS: IL-1 gene cluster polymorphisms could affect the risk of disc degeneration. The effect of physical workload seems to be modified by the IL-1 gene polymorphisms.

Adult↗

PubMed2003

Smoking and overweight as predictors of hospitalization for back disorders.

STUDY DESIGN: A prospective cohort study. OBJECTIVE: To study the relationship of smoking and overweight with severe back disorders leading to hospitalization. SUMMARY OF BACKGROUND DATA: Many epidemiological studies have shown an association between smoking or overweight and back pain, but the results are still equivocal. Longitudinal studies are few. METHODS: A cohort of metal industry employees (n = 902) was studied for lifestyle, work history, and health in 1973 by questionnaire and interview. The weight of the subjects was measured and body mass index (kg/m2) was calculated. Based on intensity and duration, smoking was categorized as: never smoked (reference), stopped smoking, smoked 9 pack-years. Information on hospital admissions from 1973 to 2000 from the Finnish Hospital Discharge Register was linked to the data. Seventy-five individuals had been admitted to hospital because of back disorders. Intervertebral disc disorders and other common back disorders were analyzed separately. Cox proportional hazards regression was used to estimate the time between the assessment of potential risk factors and the first hospitalization for a back disorder. RESULTS: The rate ratio of heavy smokers (>9 pack-years) for hospitalization because of intervertebral disc disorders was 3.4 (95% confidence interval 1.3-9.0) as compared with never-smokers, allowing for other risk factors. Accordingly, the rate ratio of body mass index >27.5 kg/m2 was 2.7 (1.1-6.45) as compared with people with normal weight. The results retained when patients with chronic back disease at baseline were excluded from the analyses. Other back-related diagnoses of hospitalization were not consistently associated with smoking or overweight. CONCLUSION: Heavy smoking and overweight predicted hospitalization for intervertebral disc disorders.

Aged↗

PubMed2002

COL9A3 gene polymorphism and obesity in intervertebral disc degeneration of the lumbar spine: evidence of gene-environment interaction.

STUDY DESIGN: Cross-sectional. OBJECTIVES: To evaluate the interaction between the COL9A3 gene polymorphism and persistent obesity in relation to lumbar disc degeneration. SUMMARY OF BACKGROUND DATA: Obesity has been suggested to be a risk factor for disc degeneration. There is some indication for an association between collagen IX genes and lumbar disc disease characterized by sciatica. However, the interaction between those factors in their influences on the risk of disc degeneration has not been studied. METHODS: Blood samples from 135 middle-aged men who had undergone magnetic resonance imaging (MRI) of the lumbar spine were analyzed for the presence of an arginine to tryptophan change in the COL9A3 gene (Trp3 allele). The men represented three occupations: 41 were machine drivers, 42 were carpenters, and 52 were office workers. The discs L2/L3-L5/S1 were evaluated on MRI, using decreased signal intensity of the nucleus pulposus, posterior disc bulges, and decreased disc height as signs of disc degeneration. Based on self-reports on body height and weight currently and at the age of 25 years, obesity history was classified as no obesity, persistent obesity, and other. Rothman's synergy index was used as a measure of interaction between two factors. RESULTS: The Trp3 allele and persistent obesity acted synergistically to increase the risk of dark nucleus pulposus, posterior disc bulge, and decreased disc height at L4/L5; of multilevel posterior disc bulges; and of decreased disc height. From 45% to 71% of disc degeneration among persistently obese individuals with the Trp3 allele could be attributed to the synergism of these two factors. CONCLUSION: The effect of obesity on lumbar disc degeneration seems to be modified by the collagen IX gene polymorphism, so that people who carry the Trp3 allele are at increased risk if they are persistently obese.

Alleles↗

PubMed2002

Work stress and risk of cardiovascular mortality: prospective cohort study of industrial employees.

OBJECTIVE: To examine the association between work stress, according to the job strain model and the effort-reward imbalance model, and the risk of death from cardiovascular disease. DESIGN: Prospective cohort study. Baseline examination in 1973 determined cases of cardiovascular disease, behavioural and biological risks, and stressful characteristics of work. Biological risks were measured at 5 year and 10 year follow up. SETTING: Staff of a company in the metal industry in Finland. PARTICIPANTS: 812 employees (545 men, 267 women) who were free from cardiovascular diseases at baseline. MAIN OUTCOME MEASURE: Cardiovascular mortality 1973-2001 from the national mortality register. RESULTS: Mean length of follow up was 25.6 years. After adjustment for age and sex, employees with high job strain, a combination of high demands at work and low job control, had a 2.2-fold (95% confidence interval 1.2 to 4.2) cardiovascular mortality risk compared with their colleagues with low job strain. The corresponding risk ratio for employees with effort-reward imbalance (low salary, lack of social approval, and few career opportunities relative to efforts required at work) was 2.4 (1.3 to 4.4). These ratios remained significant after additional adjustment for occupational group and biological and behavioural risks at baseline. High job strain was associated with increased serum total cholesterol at the 5 year follow up. Effort-reward imbalance predicted increased body mass index at the 10 year follow up. CONCLUSIONS: High job strain and effort-reward imbalance seem to increase the risk of cardiovascular mortality. The evidence from industrial employees suggests that attention should be paid to the prevention of work stress.

Adult↗