Virginia A. Casey

Protective Association of Milk Intake on the Risk of Hip Fracture: Results from the Framingham Original Cohort

Dairy foods are rich in bone‐beneficial nutrients, yet the role of dairy foods in hip fracture prevention remains controversial. Our objective was to evaluate the association of milk, yogurt, cheese, cream, and milk + yogurt intakes with incident hip fracture in the Framingham Original Cohort. A total of 830 men and women from the Framingham Original Cohort, a prospective cohort study, completed a food‐frequency questionnaire (1988 to 1989) and were followed for hip fracture until 2008. In this population‐based study, Cox‐proportional hazards regression was used to estimate hazard ratios (HR) by categories of energy‐adjusted dairy intake (servings/wk), adjusting for standard confounders and covariates. The exposure was energy‐adjusted intakes of milk, yogurt, cheese, cream, and milk + yogurt (servings/wk). Risk of hip fracture over the follow‐up was the primary outcome; the hypothesis being tested was formulated after data collection. The mean age at baseline was 77 years (SD 4.9, range 68 to 96). Ninety‐seven hip fractures occurred over the mean follow‐up time of 11.6 years (range 0.04 to 21.9 years). The mean ± SD (servings/wk) of dairy intakes at baseline were: milk = 6.0 ± 6.4; yogurt = 0.4 ± 1.3; cheese = 2.6 ± 3.1; and cream = 3.4 ± 5.5. Participants with medium (>1 and <7 servings/wk) or higher (≥7 servings/wk) milk intake tended to have lower hip fracture risk than those with low (≤1 serving/wk) intake (high versus low intake HR 0.58, 95% confidence interval [CI] 0.31–1.06, p = 0.078; medium versus low intake HR 0.61, 95% CI 0.36–1.08, p = 0.071; p trend = 0.178]. There appeared to be a threshold for milk, with 40% lower risk of hip fracture among those with medium/high milk intake compared with those with low intake (p = 0.061). A similar threshold was observed for milk + yogurt intake (p = 0.104). These associations were further attenuated after adjustment for femoral neck bone mineral density. No significant associations were seen for other dairy foods (p range = 0.117 to 0.746). These results suggest that greater intakes of milk and milk + yogurt may lower risk for hip fracture in older adults through mechanisms that are partially, but not entirely, attributable to effects on bone mineral density.

Foot Disorders, Foot Posture, and Foot Function: The Framingham Foot Study

Introduction Foot disorders are common among older adults and may lead to outcomes such as falls and functional limitation. However, the associations of foot posture and foot function to specific foot disorders at the population level remain poorly understood. The purpose of this study was to assess the relation between specific foot disorders, foot posture, and foot function. Methods Participants were from the population-based Framingham Foot Study. Quintiles of the modified arch index and center of pressure excursion index from plantar pressure scans were used to create foot posture and function subgroups. Adjusted odds ratios of having each specific disorder were calculated for foot posture and function subgroups relative to a referent 3 quintiles. Results Pes planus foot posture was associated with increased odds of hammer toes and overlapping toes. Cavus foot posture was not associated with the foot disorders evaluated. Odds of having hallux valgus and overlapping toes were significantly increased in those with pronated foot function, while odds of hallux valgus and hallux rigidus were significantly decreased in those with supinated function. Conclusions Foot posture and foot function were associated with the presence of specific foot disorders.

Dietary Acid Load Is Not Associated with Lower Bone Mineral Density Except in Older Men

High dietary acid load may be detrimental to bone mineral density (BMD), although sufficient calcium intake might neutralize this effect. In observational studies, the association between BMD and dietary acid load, estimated by net endogenous acid production (NEAP) and potential renal acid load (PRAL), has been inconsistent, and the potential modifying effect of calcium intake has not been assessed. We therefore examined the cross-sectional associations of estimated NEAP and PRAL with BMD in the Framingham Osteoporosis Study. We hypothesized that higher estimated NEAP and PRAL would be associated with lower BMD, but only among those with total calcium intake < 800 mg/d. BMD of the femoral neck and lumbar spine was measured, and estimated NEAP and PRAL were calculated via FFQ among 1069 Framingham Original (1988-1989, 1992-1993; 62% women, mean age 76 y) and 2919 Offspring (1996-2001; 56% women, mean age 60 y) cohort participants. Cohort- and sex-specific ANCOVA was used to calculate multivariable-adjusted mean BMD for estimated NEAP and PRAL quartiles. Assuming no uncontrolled confounding, estimated NEAP, but not PRAL, was inversely associated with femoral neck BMD (P-trend = 0.04) in Original cohort men, whereas neither was associated with lumbar spine BMD. Estimated NEAP and PRAL were not associated with BMD at any site among Original cohort women or Offspring cohort men and women. There were no significant interactions between either estimated NEAP or PRAL and total calcium intake. These results suggest that, with a possible exception of older men, dietary acid load does not have a measureable negative effect on bone health, regardless of total calcium intake.

Correlations of clinical and laboratory measures of balance in older men and women

It is known that impaired balance is associated with falls in older adults; however, there is no accepted gold standard on how balance should be measured. Few studies have examined measures of postural sway and clinical balance concurrently in large samples of community‐dwelling older adults. We examined the associations among 4 types of measures of laboratory‐ and clinic‐based balance in a large population‐based cohort of older adults.

Associations of foot posture and function to lower extremity pain: results from a population-based foot study.

Studies have implicated foot posture and foot function as risk factors for lower extremity pain. Empirical population‐based evidence for this assertion is lacking; therefore, the purpose of this study was to evaluate cross‐sectional associations of foot posture and foot function to lower extremity joint pain in a population‐based study of adults.

Hallux valgus and plantar pressure loading: the Framingham foot study

BackgroundHallux valgus (HV), a common structural foot deformity, can cause foot pain and lead to limited mobility. The purpose of this study was to evaluate differences in plantar pressure and force during gait by HV status in a large population-based cohort of men and women.MethodsA trained examiner performed a validated physical examination on participants’ feet and recorded the presence of hallux valgus and other specific foot disorders. Each foot was classified into one of four mutually exclusive groups based on the foot examination. Foot groups were: (i) HV only, (ii) HV and at least one additional foot disorder (FD), (iii) no HV but at least one other FD, and (iv) neither HV nor FD (referent). Biomechanical data for both feet were collected using Tekscan Matscan. Foot posture during quiet standing, using modified arch index (MAI), and foot function during gait, using center of pressure excursion index (CPEI), were calculated per foot. Further, walking scans were masked into eight sub-regions using Novel Automask, and peak pressure and maximum force exerted in each region were calculated.ResultsThere were 3205 participants, contributing 6393 feet with complete foot exam data and valid biomechanical measurements. Participants with HV had lower hallucal loading and higher forces at lesser toes as well as higher MAI and lower CPEI values compared to the referent. Participants with HV and other FDs were also noted to have aberrant rearfoot forces and pressures.ConclusionsThese results suggest that HV alters foot loading patterns and pressure profiles. Future work should investigate how these changes affect the risk of other foot and lower extremity ailments.

Characteristics Associated With Hallux Valgus in a Population-Based Foot Study of Older Adults†

Hallux valgus (HV) is common in older adults, but limited studies of risk factors have reported conflicting results. This cross‐sectional analysis examined the association of HV with foot pain and other characteristics in older adults.

Factors affecting center of pressure in older adults: the Framingham Foot Study

BackgroundAlthough aberrant foot movement during gait has been associated with adverse outcomes in the lower extremities in clinical patients, few studies have analyzed population differences in foot function. The purpose of this study was to assess demographic differences in foot function in a large population-based study of community-dwelling adults.MethodsParticipants in this study were from the Framingham Foot Study. Walking data were collected from both feet using a Tekscan Matscan pressure mat. Foot function was characterized using the center of pressure excursion index (CPEI). T-tests were used to assess differences between population subsets based on sex, and in men and women separately, age, body mass index (BMI), physical activity and in women, past high heel use.ResultsThere were 2111 participants included in this analysis. Significant differences in CPEI were noted by sex (p< 0.0001), by age in women (p = 0.04), and by past high heel use in women (p = 0.04).ConclusionsFoot function during gait was affected by sex, as well as by age and shoe-wear in women, but not by BMI or physical activity. Future work will evaluate possible relations between CPEI and outcomes such as falls, sarcopenia, and lower extremity function.

Characteristics Associated with Hallux Valgus in a Population-Based Study of Older Adults: The Framingham Foot Study

Hallux valgus (HV) is common in older adults, but limited studies of risk factors have reported conflicting results. This cross‐sectional analysis examined the association of HV with foot pain and other characteristics in older adults.

Foot Function, Foot Pain, and Falls in Older Adults: The Framingham Foot Study

Background: Although foot pain has been linked to fall risk, contributions of pain severity, foot posture, or foot function are unclear. These factors were examined in a cohort of older adults. Objective: The purpose of this study was to examine the associations of foot pain, severity of foot pain, and measures of foot posture and dynamic foot function with reported falls in a large, well-described cohort of older adults from the Framingham Foot Study. Methods: Foot pain, posture, and function were collected from Framingham Foot Study participants who were queried about falls over the past year (0, 1, and ≥2 falls). Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the relation of falls with foot pain, pain severity, foot posture, and foot function adjusting for covariates. Results: The mean age of the 1,375 participants was 69 years; 57% were female, and 21% reported foot pain (40% mild pain, 47% moderate pain, and 13% severe pain). One-third reported falls in the past year (1 fall: n = 263, ≥2 falls: n = 152). Foot pain was associated with a 62% increased odds of recurrent falls. Those with moderate and severe foot pain showed increased odds of ≥2 falls (OR 1.78, CI 1.06-2.99, and OR 3.25, CI 1.65-7.48, respectively) compared to those with no foot pain. Foot function was not associated with falls. Compared to normal foot posture, those with planus foot posture had 78% higher odds of ≥2 falls. Conclusion: Higher odds of recurrent falls were observed in individuals with foot pain, especially severe foot pain, as well as in individuals with planus foot posture, indicating that both foot pain and foot posture may play a role in increasing the risk of falls among older adults.