W. Michael O'Fallon

Effect of Fluoride Treatment on the Fracture Rate in Postmenopausal Women with Osteoporosis

Although fluoride increases bone mass, the newly formed bone may have reduced strength. To assess the effect of fluoride treatment on the fracture rate in osteoporosis, we conducted a four-year prospective clinical trial in 202 postmenopausal women with osteoporosis and vertebral fractures who were randomly assigned to receive sodium fluoride (75 mg per day) or placebo. All received a calcium supplement (1500 mg per day). Sixty-six women in the fluoride group and 69 women in the placebo group completed the trial. As compared with the placebo group, the treatment group had increases in median bone mineral density of 35 percent (P less than 0.0001) in the lumbar spine (predominantly cancellous bone), 12 percent (P less than 0.0001) in the femoral neck, and 10 percent (P less than 0.0001) in the femoral trochanter (sites of mixed cortical and cancellous bone), but the bone mineral density decreased by 4 percent (P less than 0.02) in the shaft of the radius (predominantly cortical bone). The number of new vertebral fractures was similar in the treatment and placebo groups (163 and 136, respectively; P not significant), but the number of nonvertebral fractures was higher in the treatment group (72 vs. 24; P less than 0.01). Fifty-four women in the fluoride group and 24 in the placebo group had side effects sufficiently severe to warrant dose reduction; the major side effects were gastrointestinal symptoms and lower-extremity pain. We conclude that fluoride therapy increases cancellous but decreases cortical bone mineral density and increases skeletal fragility. Thus, under the conditions of this study, the fluoride-calcium regimen was not effective treatment for postmenopausal osteoporosis.

Bone density and fracture risk in men

We evaluated different definitions of osteoporosis in a population‐based sample of 348 men (age 22–90 years) compared with 351 women (age 21–93 years). Thirty‐six men (10%) and 46 women (13%) had a history of osteoporotic fracture (hip, spine, or distal forearm due to moderate trauma at ≥ age 35). In logistic regression analysis, osteoporotic fracture risk was associated with bone mineral density (BMD) at all sites (neck, trochanter, total hip, lumbar spine, and total wrist) in both genders (p < 0.001) except spinal BMD in men. After adjusting for age, total hip BMD was the strongest predictor of fracture risk in women (odds ratio [OR] per 1 SD decline, 2.4; 95% confidence interval [CI], 1.6–3.7), while wrist BMD was best in men (OR, 1.5; 95% CI, 1.1–2.0). Among men but not women, bone mineral apparent density (BMAD) was a better predictor of fracture than BMD (wrist BMAD OR, 1.7; 95% CI, 1.3–2.3). Hip BMD/BMAD decreased linearly from age 20 years onward in both genders, while spinal BMD/BMAD declined after age 40 in women but not in men. In both genders, total wrist BMD/BMAD decreased after age 50. By World Health Organization criteria, the age‐adjusted prevalence of osteoporosis at the hip, spine, or wrist was 35% among women ≥50 years of age. A similar approach (BMD > 2.5 SD below the young male mean) produced an osteoporosis prevalence rate in men ≥50 years of age of 19%. Thus, bone density predicts fracture risk in men as it does in women, and the prevalence of osteoporosis in men, using sex‐specific normal values, is substantial. These observations indicate a need for better prevention and treatment strategies for men.

Epidemiology of Sarcopenia

OBJECTIVES: To examine patterns of muscle mass change with aging and to estimate the prevalence of sarcopenia.

Trends in the incidence and mortality of systemic lupus erythematosus, 1950–1992

OBJECTIVE To describe trends in systemic lupus erythematosus (SLE) incidence and mortality over the past 4 decades. METHODS Using the Rochester Epidemiology Project resources, medical records were screened to identify all Rochester, Minnesota residents with any SLE-associated diagnoses, discoid lupus, positivity for antinuclear antibodies, and/or false-positive syphilis test results determined between January 1, 1980 and December 31, 1992. Medical records were then reviewed using a pretested data collection form in order to identify cases of SLE according to the American College of Rheumatology 1982 revised criteria for SLE. Drug-induced cases were excluded. All identified SLE patients were followed up until death, migration from the county, or October 1, 1997. These data were combined with similar data from the same community obtained between 1950 and 1979, and trends in the SLE incidence and mortality over time were calculated. RESULTS Of the 430 medical records reviewed, 48 newly diagnosed cases of SLE (42 women and 6 men) were identified between 1980 and 1992. The average incidence rate (age- and sex-adjusted to the 1970 US white population) was 5.56 per 100,000 (95% confidence interval [95% CI] 3.93-7.19), compared with an incidence of 1.51 (95% CI 0.85-2.17) in the 1950-1979 cohort. The age- and sex-adjusted prevalence rate as of January 1, 1993 was approximately 1.22 per 1,000 (95% CI 0.97-1.47). Survival among SLE patients was significantly worse than in the general population (P = 0.017 compared with the 1980-1992 cohort, and P < 0.0001 compared with the 1950-1979 cohort, by log-rank test). Cox proportional hazards modeling demonstrated a statistically significant improvement in the survival rate over time (P = 0.035). CONCLUSION Over the past 4 decades, the incidence of SLE has nearly tripled, and there has been a statistically significant improvement in survival. These findings are likely due to a combination of improved recognition of mild disease and better approaches to therapy.

Risk of connective-tissue diseases and other disorders after breast implantation.

Background We conducted a population-based, retrospective study to examine the risk of a variety of connective-tissue diseases and other disorders after breast implantation. Methods All women in Olmsted County, Minnesota, who received a breast implant between January 1, 1964, and December 31, 1991 (the case subjects), were studied. For each case subject, two women of the same age (within three years) from the same population who had not received a breast implant and who underwent a medical evaluation within two years of the date of the implantation in the case subject were selected as control subjects. Each womans inpatient and outpatient medical record was reviewed for the occurrence of various connective-tissue diseases, certain other disorders thought to have an autoimmune pathogenesis (e.g., Hashimotos thyroiditis), and cancer other than breast cancer, as well as related symptoms and abnormal results of laboratory tests. The case subjects were categorized according to whether they received implants ...

Relationship of bone turnover to bone density and fractures.

To assess the influence of bone turnover on bone density and fracture risk, we measured serum levels of osteocalcin (OC), bone alkaline phosphatase (BAP), and carboxy‐terminal propeptide of type I procollagen (PICP), as well as 24‐h urine levels of cross‐linked N‐telopeptides of type I collagen (NTx) and the free pyridinium cross‐links, pyridinoline (Pyd) and deoxypyridinoline (Dpd), among 351 subjects recruited from an age‐stratified random sample of Rochester, Minnesota women. PICP, NTx, and Dpd were negatively associated with age among the 138 premenopausal women. All of the biochemical markers were positively associated with age among the 213 postmenopausal women, and the prevalence of elevated turnover (>1 standard deviation [SD] above the premenopausal mean) varied from 9% (PICP) to 42% (Pyd). After adjusting for age, most of the markers were negatively correlated with bone mineral density (BMD) of the hip, spine, or forearm as measured by dual‐energy X‐ray absorptiometry, and women with osteoporosis were more likely to have high bone turnover. A history of osteoporotic fractures of the hip, spine, or distal forearm was associated with reduced hip BMD and with elevated Pyd. After adjusting for lower BMD and increased bone resorption, reduced bone formation as assessed by OC was also associated with prior osteoporotic fractures. These data indicate that a substantial subset of elderly women has elevated bone turnover, which appears to adversely influence BMD and fracture risk. Combined biochemical and BMD screening may provide better prediction of future fracture risk than BMD alone.

The unchanging pattern of subarachnoid hemorrhage in a community

The average annual incidence of subarachnoid hemorrhage (SAH) from aneurysm rupture in Rochester, Minnesota, has remained remarkably constant at about 11 per 100,000 population. Age-specific incidence increased with age. Survival after SAH depended on: (1) clinical grade, (2) time after onset of SAH, and (3) presence of intracerebral hematoma. Among those who survived to receive medical attention, 48% were clinical grade 1 or 2, 20% were grade 3, and 32% were grade 4 or 5. Proved rebleeding occurred within 10 days of the first SAH in 20% of patients who survived until hospital admission.

Complications Leading to Surgery after Breast Implantation

BACKGROUND Local complications that require additional surgical procedures are an important problem for women with breast implants. METHODS We studied 749 women who lived in Olmsted County, Minnesota, and received a first breast implant at the Mayo Clinic between 1964 and 1991. We identified complications that occurred after the initial procedure and after any subsequent implantation. A complication was defined as a surgical procedure performed for any of the following reasons: capsular contracture; rupture of the implant; hematoma or bleeding; infection or seroma of the wound; chronic pain; extrusion, leakage, or sweating of the implant; necrosis of the nipple, areola, or flap; malfunction of the filler port of a tissue expander; and wound dehiscence. RESULTS During follow-up (mean, 7.8 years; range, 0 to 25.8), 208 (27.8 percent) of the women underwent 450 additional implant-related surgical procedures. Ninety-one (20.2 percent) were anticipated, staged procedures or were done because the patient requested a size change or aesthetic improvement, and 359 procedures (79.8 percent) had at least one clinical indication (thus constituting a complication). Complications occurred in 178 (23.8 percent) of the 749 women and involved 274 (18.8 percent) of the 1454 breasts with implants and 321 (18.8 percent) of the 1703 implants. The most frequent problem was capsular contraction (272 cases), followed by rupture of the implant (60), hematoma (55), and wound infection (23). The rate of complications was significantly lower (P<0.001) among women with cosmetic implants (6.5 percent at one year, 12 percent at five years) than among women who underwent implantation after mastectomy for breast cancer (21.8 percent at one year, 34 percent at five years) or prophylactic mastectomy (17.3 percent at one year, 30.4 percent at five years). CONCLUSIONS Women who have had breast implantation frequently experience local complications during the subsequent five years. Complications were significantly less frequent among patients who received implants for cosmetic reasons than among those who received implants after mastectomy for cancer or for cancer prophylaxis.

The epidemiology of rheumatoid arthritis in Rochester, Minnesota, 1955–1985

OBJECTIVE To describe trends in the epidemiology of rheumatoid arthritis (RA) over a period of 30 years in a population-based cohort. METHODS An inception cohort of Rochester, Minnesota residents who were > or =35 years of age and had RA (as defined by the 1987 American College of Rheumatology criteria for RA) first diagnosed between January 1, 1955 and January 1, 1985 was assembled and followed up until January 1, 1995. Incidence rates were age- and sex-adjusted to the 1970 US white population. Prevalence of RA in this cohort was estimated on January 1, 1985. A birth-cohort analysis was performed by calculating and comparing incidence rates in each of 16 birth cohorts. RESULTS Of the 425 Rochester residents who fulfilled the inclusion criteria, there were 113 men (26.6%) and 312 women (73.4%), with a mean age at diagnosis of 60.2 years. The mean followup time was 15.1 years. The overall age- and sex-adjusted annual incidence of RA among Rochester, Minnesota residents > or =35 years of age (1955-1985) was 75.3 per 100,000 population (95% confidence interval 68.0-82.5). This incidence was approximately double in women compared with that in men and increased steadily with age, until age 85, after which the incidence of RA decreased. Secular trends in the incidence of RA over the entire study period were demonstrated. The overall prevalence of RA on January 1, 1985 was approximately 1%. The birth-cohort analysis showed peak incidence rates in the 1880-1895 birth cohorts. CONCLUSION The epidemiology of RA is dynamic. The findings in this study lend further support to the hypothesis of a host-environment interaction in the pathogenesis of RA.

Long-term effects of calcium supplementation on serum parathyroid hormone level, bone turnover, and bone loss in elderly women

We report a 4‐year randomized, double‐blind, placebo‐controlled clinical trial in 236 normal postmenopausal women (mean age ± SE, 66.3 ± 0.2 years) who were randomized to a calcium (1600 mg/day as the citrate) or placebo group. The women were seen every 6 months; 177 completed the trial. Net percentage changes in each group are given relative to baseline. The differences in net percentage changes (calcium group minus placebo group) in medians were: for lumbar spine bone density, 2.0% (p < 0.001) at year 1 and 0.3% (not significant) at year 4; for proximal femur bone density, 1.3% (p = 0.003) at year 1 and 1.3% (p = 0.015) at year 4; and for total body bone mineral, 0.4% (p = 0.002) at year 1 and 0.9% (p = 0.017) at year 4. Similar differences at year 4 were: −18.9% (p = 0.002) for parathyroid hormone (PTH), −11.9% (p = 0.026) for serum osteocalcin, and −32.2% (p = 0.003) for urine free pyridinoline. We conclude that long‐term administration of calcium supplements to elderly women partially reverses age‐related increases in serum PTH level and bone resorption and decreases bone loss. However, the effects on bone loss were weaker than those reported for estrogen, bisphosphonates, or calcitonin therapy, indicating that calcium supplements alone cannot substitute for these in treating established osteoporosis. Nonetheless, because of their safety, high tolerance, and low expense, calcium supplements may be a useful preventive measure for elderly postmenopausal women whose bone mineral density values are normal for their age.