Egan, Kathleen S.

AbstractBackground and Purpose. The causes of lumbopelvic imbalances in standing have been widely accepted by physical therapists, but there is a lack of scientific evidence available to support them. We examined the association between 9 variables and pelvic inclination and lumbar lordosis during relaxed standing. Subjects. Thirty men and 30 women with chronic low back pain (CLBP) for at least 4 months were examined (mean age=54.9 years, SD=9, range=40.4–69.8). Methods. Multiple linear regression modeling was used to assess the association of pelvic inclination and the magnitude of lumbar lordosis in standing with age, sex, body mass index (BMI), Oswestry Back Pain Disability Questionnaire (ODQ) scores, physical activity level, hip flexor muscle length, abdominal muscle force, and range of motion (ROM) for lumbar flexion and extension. Results. In women, age, BMI, and ODQ scores were associated univariately and multivariately with pelvic inclination. In men, lumbar extension ROM was related univariately to pelvic inclination; age, lumbar extension ROM, and ODQ scores were associated multivariately. Lumbar lordosis was associated univariately with only lumbar extension ROM for women and men. A weak correlation was found between angle of pelvic inclination and magnitude of lumbar lordosis in standing (r=.31 for women, r=.37 for men). Conclusion and Discussion. The odds ratio of having CLBP is increased if the score on the double-leg lowering test for abdominal muscles exceeds 50 degrees for men and 60 degrees for women. In patients with CLBP, the magnitude of the lumbar lordosis and pelvic inclination in standing is not associated with the force production of the abdominal muscles.

Abstract Interleukin 1αa (IL-1α), interleukin 1β (IL-1β), and interleukin 6 (IL-6) are cytokines with potent bone-resorbing effects; some of these biologic effects are opposed by interleukin-1 receptor antagonist (IL-1ra). In vitro and animal model studies suggest that these cytokines are paracrine mediators of the increased bone resorption associated with estrogen deficiency, and increases in their production also could contribute to age-related bone loss. Therefore, we measured serum concentrations of these cytokines in 80 normal women who were 24-87 years old. IL-6 concentration correlated highly with age (p > 0.001) and increased three-fold during life. However, multiple-regression analysis showed no significant correlation between serum IL-6 levels and menopausal status, serum estradiol concentration, or markers for bone turnover (serum bone alkaline phosphatase, osteocalcin, carboxyl-terminal telopeptide of type I collagen, or 24 h urinary free pyridinoline excretion). Serum IL-1α, IL-1β, or IL-1ra level did not change with age and, by multiple-regression analysis, did not correlate with markers of bone turnover, except IL-1ra weakly with ICTP. We found no relationship between bone-resorbing cytokines and ovarian function. Although the large age-related increase in serum IL-6 concentration could contribute to age-related bone loss, the lack of correlation with markers for bone turnover argues against this. However, based on the strong evidence in experimental animals that these cytokines are involved in estrogen action on bone, further studies in humans are warranted.

Abstract Bone mass and its mineral content are under genetic control. The vitamin D receptor (VDR) gene has been shown to be a major locus for genetic effects on bone mineral density (BMD), and polymorphisms in this gene accounted for a large proportion of genetic variance in BMD in an Australian population. In this study, we investigated whether similar associations are present in a North American population. We studied 139 normal healthy women (age 53.2 ± 14.5, mean ± SD) and 43 severely osteoporotic postmenopausal women (age 65.8 ± 5.9). In the 127 of them with complete genetic studies, the distribution of genotypes, determined by polymerase chain reaction on leukocyte DNA samples, agreed closely with that in the Australian population. BMD was strongly related to age and weight, and, thus was adjusted for these parameters prior to genetic analysis. We found that age modulated the effect of VDR genotypes on femoral neck BMD (FN-BMD) (TaqI, p = 0.036;BsmI, p = 0.118; ApaI, p = 0.041) such that the effect of genotype was greatest among younger (premenopausal) women and declined with age so that there was no discernible difference by age 70. Among the younger women, a high FN-BMD was associated with the TT (or aa or bb) genotype while low FN-BMD was associated with the tt (or AA or BB) genotype. In osteoporotic women, although the difference in FN-BMD between alternate TaqI homozygotes (TT vs. tt) was 0.13 g/cm2 (or about 18%), the overall difference among the genotype groups was not significant (TaqI, p = 0.13; BsmI, p = 0.21; ApaI, p = 0.09), possibly due to the small sample of osteoporotic women. There was no relationship of VDR genotype to lumbar spine BMD. We conclude that the VDR gene modulates differences in BMD in premenopausal women. Subsequent interaction of the gene and environmental factors and the role of VDR genotypes in predisposing to osteoporosis needs further study.