Genetic Risk Score for Serum 25-Hydroxyvitamin D Concentration Helps to Guide Personalized Vitamin D Supplementation in Healthy Finnish Adults.

BACKGROUND: Genetic factors modify serum 25-hydroxyvitamin D [25(OH)D] concentration and can affect the optimal intake of vitamin D. OBJECTIVES: We aimed to personalize vitamin D supplementation by applying knowledge of genetic factors affecting serum 25(OH)D concentration. METHODS: We performed a genome-wide association study of serum 25(OH)D concentration in the Finnish Health 2011 cohort (n = 3339) using linear regression and applied the results to develop a population-matched genetic risk score (GRS) for serum 25(OH)D. This GRS was used to tailor vitamin D supplementation for 96 participants of a longitudinal Digital Health Revolution (DHR) Study. The GRS, serum 25(OH)D concentrations, and personalized supplementation and dietary advice were electronically returned to participants. Serum 25(OH)D concentrations were assessed using immunoassays and vitamin D intake using FFQs. In data analyses, cross-sectional and repeated-measures statistical tests and models were applied as described in detail elsewhere. RESULTS: GC vitamin D-binding protein and cytochrome P450 family 2 subfamily R polypeptide 1 genes showed genome-wide significant associations with serum 25(OH)D concentration. One single nucleotide polymorphism from each locus (rs4588 and rs10741657) was used to develop the GRS. After returning data to the DHR Study participants, daily vitamin D supplement users increased from 32.6% to 60.2% (P = 6.5 × 10-6) and serum 25(OH)D concentration from 64.4 ± 20.9 nmol/L to 68.5 ± 19.2 nmol/L (P = 0.006) between August and November. Notably, the difference in serum 25(OH)D concentrations between participants with no risk alleles and those with 3 or 4 risk alleles decreased from 20.7 nmol/L to 8.0 nmol/L (P = 0.0063). CONCLUSIONS: We developed and applied a population-matched GRS to identify individuals genetically predisposed to low serum 25(OH)D concentration. We show how the electronic return of individual genetic risk, serum 25(OH)D concentrations, and factors affecting vitamin D status can be used to tailor vitamin D supplementation. This model could be applied to other populations and countries.

Sports, smoking, and overweight during adolescence as predictors of sciatica in adulthood: a 28-year follow-up study of a birth cohort.

Lifestyle factors such as smoking, obesity, and level of physical activity predict low back pain (LBP) and sciatica. The authors investigated whether participating in sports, smoking, and being overweight or obese at 14 years of age predicted hospitalizations due to LBP or sciatica in adulthood. In 1980, at the age of 14 years, a total of 11,399 members of the 1966 Northern Finland Birth Cohort returned the postal questionnaire. Patients from the 1966 Northern Finland Birth Cohort who were hospitalized because of LBP or sciatica were followed to the end of 2008 through the Finnish Hospital Discharge Register. Data were analyzed using Cox's proportional hazards multistate model with the Markov clock forward time scale. During follow-up, 119 females (2.7%) and 254 males (5.6%) had been hospitalized at least once because of LBP or sciatica. Among females, overweight was associated with an increased risk of second-time hospitalization for surgical treatment for sciatica (hazard ratio = 7.1, 95% confidence interval: 1.5, 34.4). Among males, smoking was associated with an increased risk of first-time nonsurgical hospitalization (hazard ratio = 1.8, 95% confidence interval: 1.2, 2.7) and second-time surgical hospitalization (hazard ratio = 3.2, 95% confidence interval: 1.2, 8.2). The authors found potentially modifiable risk factors in adolescence that predicted hospital treatments for low back disorders during adolescence and young adulthood.

Is insufficient quantity and quality of sleep a risk factor for neck, shoulder and low back pain? A longitudinal study among adolescents.

The quantity and quality of adolescents' sleep may have changed due to new technologies. At the same time, the prevalence of neck, shoulder and low back pain has increased. However, only a few studies have investigated insufficient quantity and quality of sleep as possible risk factors for musculoskeletal pain among adolescents. The aim of the study was to assess whether insufficient quantity and quality of sleep are risk factors for neck (NP), shoulder (SP) and low back pain (LBP). A 2-year follow-up survey among adolescents aged 15-19 years was (2001-2003) carried out in a subcohort of the Northern Finland Birth Cohort 1986 (n = 1,773). The outcome measures were 6-month period prevalences of NP, SP and LBP. The quantity and quality of sleep were categorized into sufficient, intermediate or insufficient, based on average hours spent sleeping, and whether or not the subject suffered from nightmares, tiredness and sleeping problems. The odds ratios (OR) and 95% confidence intervals (CI) for having musculoskeletal pain were obtained through logistic regression analysis, adjusted for previously suggested risk factors and finally adjusted for specific pain status at 16 years. The 6-month period prevalences of neck, shoulder and low back pain were higher at the age of 18 than at 16 years. Insufficient quantity or quality of sleep at 16 years predicted NP in both girls (OR 4.4; CI 2.2-9.0) and boys (2.2; 1.2-4.1). Similarly, insufficient sleep at 16 years predicted LBP in both girls (2.9; 1.7-5.2) and boys (2.4; 1.3-4.5), but SP only in girls (2.3; 1.2-4.4). After adjustment for pain status, insufficient sleep at 16 years predicted significantly only NP (3.2; 1.5-6.7) and LBP (2.4; 1.3-4.3) in girls. Insufficient sleep quantity or quality was an independent risk factor for NP and LBP among girls. Future studies should test whether interventions aimed at improving sleep characteristics are effective in the prevention and treatment of musculoskeletal pain.

Reproducibility and reference values of inclinometric balance and isometric trunk muscle strength measurements in Finnish young adults.

The objectives of the study were to evaluate the reproducibility of the maximal isometric trunk muscle strength testing and inclinometric method to measure body sway and to establish reference values for these measurements in young Finnish adults. Reproducibility was assessed with 2 repeated measurements. Reference values are based on the cross-sectional cohort data. Maximal isometric trunk extension, flexion, and rotations were measured in standing posture. Body sway was measured with inclinometric method. The subjects (N = 874) belonged to a subcohort of the Northern Finland Birth Cohort 1986. Intrarater reliability was assessed with 19 volunteers from the birth cohort, and interrater reliability was assessed with 15 young healthy adults. Intrarater reliability intraclass correlation coefficients (ICCs) for body sway measurements ranged from 0.39 to 0.74 and for trunk muscle strength measurements from 0.84 to 0.94. Interrater reliability ICC for body sway ranged from 0.61 to 0.85 and for trunk muscle strength from 0.84 to 0.88. Maximal muscle strength was better in men than in women, but extensor to flexor ratio was higher in women. Women had significantly better values in all body sway measurements than men. Our study showed a remarkable biological variation in isometric trunk muscle strength and inclinometric body sway. Although ICC analysis indicated good reliability, the Bland and Altman analysis revealed quite wide range of measurement error. However, reproducibility of isometric trunk muscle testing is comparable to other measurements of trunk muscle function in use. Reference values collected in our study offer valuable normative data for future studies and can be used as a tool when assessing physical capacity of healthy subjects or patients with different pathological conditions.

Three-phase bone scintigraphy in chronic epicondylitis.

OBJECTIVE: To assess the utility of 3-phase bone scintigraphy as a complementary diagnostic method in chronic epicondylitis. DESIGN: A cross-sectional study. SETTING: Hospital outpatient clinic admitting patients with musculoskeletal disorders. PARTICIPANTS: Patients (N=59; 68% women) with unilateral chronic epicondylitis. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Three-phase bone scintigraphy was performed after an intravenous injection of 550MBq (99m)technetium-labeled hydroxymethyline diphosphonate ((99m)Tc-HDP) in the patients. Blood flow and blood pool phases were graded visually as normative or abnormal. In the bone metabolic phase, the scintigraphic radiograph images were evaluated using a transmission densitometer. The ratio between maximal bone uptake of (99m)Tc-HDP in each epicondyle and the mean of that in the adjacent humerus was used as a bone uptake measure, which was compared with clinical data (pain questionnaire, pain drawing, cubital pain thresholds, muscle strength) and with work ability and lifestyle factors. RESULTS: The bone uptake of (99m)Tc-HDP of the affected epicondyle was 33% and 17% higher in men and women, respectively, compared with the corresponding healthy epicondyle (P<.001 and P=.007). High bone uptake of (99m)Tc-HDP was associated with better work ability, grip strength, and muscle performance in both sexes but was not correlated with the pain measures. Blood flow phases had a positive correlation with the duration of symptoms and a negative correlation with the bone uptake of (99m)Tc-HDP, grip strength, and work ability. CONCLUSIONS: High bone uptake of (99m)Tc-HDP among patients with chronic epicondylitis was associated with better muscle strength, work ability, and arm function. In chronic cases, a higher degree of bone uptake of (99m)Tc-HDP may thus indicate a healing response in the bone tissue.

Phenotype profiling of Modic changes of the lumbar spine and its association with other MRI phenotypes: a large-scale population-based study.

BACKGROUND CONTEXT: Modic changes (MC) are associated with low back pain. They represent vertebral endplate and adjacent vertebral marrow changes on magnetic resonance imaging (MRI), classified into three types. Because of small sample sizes, patient cohorts, and limited phenotype assessment, the morphology and involvement of MC and their association with other spinal phenotypes remain speculative. PURPOSE: We addressed and proposed a phenotypic profiling of MC and their relationship with lumbar MRI phenotypes in a large-scale population-based study. STUDY DESIGN/SETTING: A cross-sectional study of the Hong Kong Disc Degeneration Cohort. PATIENT SAMPLE: The study population consisted of 1,546 Southern Chinese volunteers. OUTCOME MEASURES: Topographical and morphological dimensions of MC, presence of disc degeneration (DD) and displacement, and Schmorl nodes were evaluated. METHODS: Axial T1-weighted and sagittal T2-weighted MRIs (3T) were assessed. RESULTS: Females were 62.4% (mean age, 49 years). The overall prevalence of MC was 21.9% (6.3% Type I and 15.5% Type II). Of all MC, 76% were located at the two lowest lumbar levels. Modic changes at the two lowest lumbar levels were more commonly located laterally (p<.001), less commonly anteriorly (p<.001), and were more extensive horizontally (p=.006) but not in vertical height compared with the upper levels. Type I MC were less common in the anterior part (p=.022), larger in size (height p=.004), and affected more likely the whole horizontal plane (p=.016) than Type II MC. Modic changes were associated with disc displacement, Schmorl nodes, and DD at the affected level (all p<.001), and the strength of association increased with the size of the lesion. Type I MC were associated more strongly with disc displacement (p=.008) and DD (p=.022) than Type II MC. CONCLUSIONS: Our large-scale MRI study is the first to definitely note that MC were size- and type-dependently significantly associated with disc pathology and endplate abnormalities. Our phenotype profiling of MC may have clinical utility.

Factors related to seeking health care among adolescents with musculoskeletal pain.

Musculoskeletal pain is common among adolescents, but little is known about the factors that affect seeking health care for the problem. We examined the care-seeking pattern among adolescents reporting musculoskeletal pain. The study consisted of adolescents aged 16 years from the 1986 Northern Finland Birth Cohort who responded to a mailed questionnaire in 2001 and reported musculoskeletal pain over the preceding 6 months (n=5052). Logistic regression analyses were performed to assess whether enabling resources, need factors, personal health habits, and psychological problems were associated with seeking health care for musculoskeletal pain. Musculoskeletal pain during the preceding 6 months was reported by 68% of boys and 83% of girls in the study population. Only 16% of boys and 20% of girls reporting pain had sought medical care. Among both boys and girls, care-seeking was associated with being a member of a sports club (boys, odds ratio [OR] 2.1; girls, OR 1.5) and having one (boys, OR 2.1; girls, OR 1.8) or at least 2 (boys, OR 2.2; girls, OR 2.1) other health disorders. In addition, it was associated with a high physical activity level (OR 1.5) and low self-rated (OR 1.5) health among girls. Reporting pain in other anatomical areas decreased the likelihood of seeking care for pain among both genders. In conclusion, relatively few adolescents with musculoskeletal pain had consulted a health professional for the problem. Being physically active (trauma), participating in organized sport (accessibility of care), and having other health problems may explain why an adolescent seeks care for musculoskeletal pain.

Genetic risk factors of disc degeneration among 12-14-year-old Danish children: a population study.

The objective of the present study was to examine the associations between eleven putative predisposing single nucleotide polymorphisms (COL9A3, COL11A2, IL1A, IL1B, IL6 and VDR) and early disc degeneration (DD). The population consisted of 12 to 14-year-old Danish children (N=352). DD was evaluated from magnetic resonance images (MRI). We analysed the association between DD and single nucleotide polymorphisms or haplotypes using logistic regression analyses. Of the 352 children studied, 73 boys and 81 girls had no MRI changes, while 30 boys and 36 girls had lumbar DD. Among girls, IL1A rs1800587 in CT/TT compared to CC resulted in OR 2.85 [1.19-6.83]. In IL6 promoter polymorphism rs1800796, the C-allele was more frequent among the subjects with DD, OR 6.71 [1.71-26.3]. Of the IL6 haplotypes, GCG was associated with DD, OR 6.46 [1.61 - 26.0]. No associations were observed among boys. Our results suggest possible roles for IL1A and IL6 in early DD among girls.

Risk factors for persistence of multiple musculoskeletal pains in adolescence: a 2-year follow-up study.

Musculoskeletal pain in multiple sites is common already in adolescence, and may lead to subsequent musculoskeletal complaints in adulthood. We examined predictive factors for the persistence of multiple musculoskeletal pains in adolescence over a 2-year time span. A postal questionnaire was administered to a subsample of the Northern Finland Birth Cohort 1986 (n=1773) when subjects were aged 16 and 18. The adjusted odds ratios (OR) and 95% confidence intervals (CI) for the possible risk factors of new-onset of multiple pains at 18 years and 2-year persistence of multiple pains were obtained using multinomial logistic regression. Multiple musculoskeletal pains were common; 43% of boys and 63% of girls at 16, and 61% of boys and 81% of girls at 18 reported pain in more than one site during the last 6 months. Moreover, multiple pains had a high persistence rate, as 75% of boys and 88% of girls with multiple pains at 16 reported multiple pains also at 18. In the multivariate analysis, emotional and behavioral problems (internalizing problems, OR 2.3; externalizing problems, OR 2.2), and high sitting time (OR 1.6) among boys, and internalizing problems (OR 3.7), high physical activity level (OR 1.6), short sleeping time (OR 1.7), and smoking (OR 1.9) among girls were predictive factors for the persistence of multiple pains. No statistically significant associations between the baseline variables and new-onset multiple pains were found. Multiple musculoskeletal pains appear to have a high tendency to persist in adolescence; both psychosocial factors and lifestyle factors contribute to this vulnerability.

Psychosocial, mechanical, and metabolic factors in adolescents' musculoskeletal pain in multiple locations: a cross-sectional study.

Recent studies indicate that adolescents often experience musculoskeletal pains in two or more body locations. However, previous studies have mainly focused on localized pains, and the determinants of multiple musculoskeletal pains in adolescents are not well known. The present study was set to evaluate the role of psychosocial, mechanical, and metabolic factors in adolescents' musculoskeletal pains in multiple locations. The study population consisted of the 1986 Northern Finland Birth Cohort; 15- to 16-year-old adolescents (n=6986), who responded to a mailed questionnaire in 2001. We assessed the associations of emotional and behavioral problems, physical activity, sitting time, sleeping time, overweight and smoking with musculoskeletal pains using multinomial logistic regression. Multiple pains were common, 23% of boys and 40% of girls reported feeling pain in at least three locations over the past 6 months. These pains were not only associated with anxious/depressed symptoms, withdrawn/depressed symptoms, somatic complaints, rule-breaking and aggressive behavior, social problems, thought and attention problems, but also with high physical activity level, long sitting time, short sleeping time and smoking, among both boys and girls. In addition, pain in three to four locations associated with overweight in girls. A high number of psychosocial, mechanical and metabolic factors associated strongly with multiple pains. In conclusion, multiple musculoskeletal pains were strongly associated with psychosocial complaints, but also with mechanical and metabolic factors. Reported musculoskeletal pains in multiple locations in adolescence may have both peripheral (trauma, decreased regenerative ability) and central (sensitivity) causes.

Musculoskeletal pain combinations in adolescents.

STUDY DESIGN: A 2-year follow-up in a birth cohort of adolescents aged 15 to 19 years. OBJECTIVE: To evaluate the prevalence of neck, shoulder, low back, peripheral (limb) pain, and combinations of pain at these anatomic locations. SUMMARY OF BACKGROUND DATA: Few previous studies have evaluated combinations of musculoskeletal pain among adolescents. METHODS: Prevalence of neck, shoulder, low back, and peripheral pain (elbow, wrist, knee, and ankle-foot pain) during the previous 6 months were obtained by questionnaire in a follow-up study of the Northern Finland Birth Cohort 1986 at 16 and 18 years of age (n = 1773). Latent class analysis was used in clustering of pain combinations at both time points. RESULTS: No pain at all in the past 6 months at 16 and 18 years was reported by 17% and 8% of girls, and 33% and 24% of boys, respectively. Only 1 pain location (neck, shoulder, low back, or peripheral pain) was reported by 21% of girls and 25% of boys at 16, and 11% of girls and 20% of boys at 18 years, while all 4 pain locations were reported by 15% of girls and 9% of boys at 16, and 27% and 15%, respectively, at 18 years. Latent class analysis resulted in 2 to 3 pain clusters in both genders at both time points. Probability of pain increased during the 2-year follow-up, with subjects more likely to belong to a cluster with a higher likelihood of pain. CONCLUSION: As very few adolescents did not report any pain, the relevance of self-reported pain is questionable without assessment of pain-related disability. The clinical relevance of these pain combinations must be evaluated in further studies.

Muscular fitness in relation to physical activity and television viewing among young adults.

PURPOSE: To study how time spent in physical activity and that in television (TV) viewing are associated with muscular fitness among young adults. METHODS: The study population consisted of a cross-sectional sample of 381 males and 493 females aged 19.1 yr (SD 0.3) from the Northern Finland Birth Cohort 1986. Muscular fitness was measured by trunk muscle strength tests (trunk extension, flexion, and rotation) and jumping height test. Time spent on moderate- to vigorous-intensity physical activity and on TV viewing was self-reported by a questionnaire. RESULTS: The most physically active young adults performed significantly better in most trunk muscle strength tests and the jumping test than the least active subjects. The mean difference between the most and least active groups was at minimum 1.6 kg (95% confidence interval (CI) = -0.5 to 3.7) and at maximum 10.6 kg (95% CI = 4.7-16.5) for different trunk muscle strength tests and at minimum 4.4 cm (95% CI = 2.7-6.1) for the jumping height test. Males and females who watched TV for >or=2 h x d(-1) performed significantly worse in trunk extension and flexion tests and females also performed worse in the jumping test compared with those who watched TV <2 h x d(-1), independent of their physical activity level. The mean difference between low and high TV users was at minimum -3.8 kg (95% CI = -6.7 to -0.9) for trunk extension and flexion strength and -1.2 cm (95% CI = -2.0 to -0.4) for jumping height in females. CONCLUSIONS: Among young adults, daily TV viewing for >or=2 h, irrespective of physical activity level, was associated with poorer muscular fitness.

Musculoskeletal pains in relation to different sport and exercise activities in youth.

PURPOSE: We examined the associations between participation in different sports and exercise activities and neck, shoulder, and low back pains in adolescents. METHODS: This population-based study included the members of the Northern Finland Birth Cohort 1986, who, at the age of 15 to 16 yr, completed a questionnaire including items about their musculoskeletal pains and participation in various sport and exercise activities (N = 6945). Logistic regression analysis was used to evaluate how musculoskeletal pains are associated a) with participation in a certain type of sport or exercise activity and b) with the clusters formed by latent class analysis (LCA) according to the adolescents' profiles of participation in different sport and exercise activities. RESULTS: Participation in certain sports showed some direct and inverse associations with musculoskeletal pains when adjusted for participation in other sports and for the amount of physical activity. However, after grouping the individuals into clusters by their participation in different sports, these associations vanished. Only the cluster characterized by boys' active participation in several sports (i.e., ice hockey, cycling, ice-skating, soccer, floorball, rinkball/bandy, swimming, roller-skating/skateboarding, Finnish baseball) had lower prevalence of neck pain compared with the physically inactive group. CONCLUSIONS: Physically active adolescents usually engage in several different sport and exercise activities, which make associations between single sports and musculoskeletal pains inconsequential in the general population of adolescents. Participation in several sports seemed to protect from harmful effects of a single risk sport. However, this finding cannot be generalized to adolescent elite athletes who are often involved in intense training for a single sport.