Allan Naimark

Obesity and Knee Osteoarthritis: The Framingham Study

STUDY OBJECTIVE To determine whether obesity preceded knee osteoarthritis and was thus a possible cause. DESIGN Cohort study with weight and other important variables measured in 1948 to 1951 (mean age of subjects, 37 years) and knee arthritis evaluated in 1983 to 1985 (mean age of subjects, 73 years). SETTING Population-based participants; a subset (n = 1420) of the Framingham Heart Study cohort. METHODS For those subjects in the Framingham Study having knee radiographs taken as part of the 18th biennial examination (1983 to 1985), we examined Metropolitan Relative Weight, a measure of weight adjusted for height at the onset of the study (1948 to 1951). Relative risks were computed as the cumulative incidence rate of radiographic knee osteoarthritis in the heaviest weight groups at examination 1 divided by the cumulative rate in the lightest 60% weight groups at examination 1. Relative risks were adjusted for age, physical activity level, and uric acid level. RESULTS In 1983 to 1985, 468 subjects (33%) had radiographic knee osteoarthritis. For men, the risk of knee osteoarthritis was increased in those in the heaviest quintile of weight at examination 1 compared with those in the lightest three quintiles (age-adjusted relative risk, 1.51; 95% confidence interval [CI], 1.14 to 1.98); risk was not increased for those in the second heaviest quintile (relative risk, 1.0). The association between weight and knee osteoarthritis was stronger in women than in men; for women in the most overweight quintile at examination 1, relative risk was 2.07 (95% CI, 1.67 to 2.55), and for those in the second heaviest group, relative risk was 1.44 (95% CI, 1.11 to 1.86). This link between obesity and subsequent osteoarthritis persisted after controlling for serum uric acid level and physical activity level, and was strongest for persons with severest radiographic disease. Obesity at examination 1 was associated with the risk of developing both symptomatic and asymptomatic osteoarthritis. CONCLUSIONS These results and other corroborative cross-sectional data show that obesity or as yet unknown factors associated with obesity cause knee osteoarthritis.

Weight Loss Reduces the Risk for Symptomatic Knee Osteoarthritis in Women: The Framingham Study

OBJECTIVE To evaluate the effect of weight loss in preventing symptomatic knee osteoarthritis in women. DESIGN Cohort analytic study. SETTING The Framingham Study, based on a sample of a defined population. PATIENTS Women who participated in the Framingham Knee Osteoarthritis Study (1983 to 1985): Sixty-four out of 796 women studied had recent-onset symptomatic knee osteoarthritis (knee symptoms plus radiographically confirmed osteoarthritis) were compared with women without disease. MEASUREMENTS Recalled date of symptom onset was used as the incident date of disease. Historical weight was defined as baseline body mass index up to 12 years before symptom onset. Change in body mass index was assessed at several intervals before the current examination. Odds ratios assessing the association between weight change and knee osteoarthritis were adjusted for age, baseline body mass index, history of previous knee injury, habitual physical activity level, occupational physical labor, smoking status, and attained education. RESULTS Weight change significantly affected the risk for the development of knee osteoarthritis. For example, a decrease in body mass index of 2 units or more (weight loss, approximately 5,1 kg) over the 10 years before the current examination decreased the odds for developing osteoarthritis by over 50% (odds ratio, 0.46; 95% Cl, 0.24 to 0.86; P = 0.02). Among those women with a high risk for osteoarthritis due to elevated baseline body mass index (greater than or equal to 25), weight loss also decreased the risk (for 2 units of body mass index, odds ratio, 0.41; P = 0.02). Weight gain was associated with a slightly increased risk for osteoarthritis, which was not statistically significant. CONCLUSION Weight loss reduces the risk for symptomatic knee osteoarthritis in women.

Intrathoracic Extramedullary Hematopoiesis Secondary to B12 and Folate Deficiency: Ct Appearance

Intrathoracic extramedullary hematopoiesis is an unusual condition, usually associated with congenital hemolytic anemias. We present a rare case due to vitamin B12 and folate deficiency diagnosed by CT-guided biopsy.

Extravasation from the unused bladder during cystography: case report

Spontaneous, asymptomatic extravasation during retrograde cystography occurred in a quadraplegic patient who had been maintained on constant Foley catheter drainage for 7 years. This phenomenon has recently been described in a few anuric patients being studied prior to renal transplant and is probably related to the chronic disuse status of the bladder. It is a self-limiting process and, in the absence of a clinical reaction, only observation is warranted.