Impact of obesity on disability, function, and physical activity: data from the Osteoarthritis Initiative.

OBJECTIVES: Older adults with obesity are at risk for osteoarthritis (OA) and are predisposed to functional decline and disability. We examined the association between obesity and disability, physical activity, and quality of life at 6 years. METHOD: Using data from the longitudinal Osteoarthritis Initiative (OAI), we analysed older adults (age ≥ 60 years) with a body mass index (BMI) at baseline ≥ 18.5 kg/m(2) (n = 2378) using standard BMI categories. Outcomes were assessed at the 6-year follow-up and included: the Late-Life Function and Disability Index (LLDI), the 12-item Short Form Health Survey (SF-12), and the Physical Activity Scale for the Elderly (PASE). Linear regression predicted outcomes based on BMI category, adjusting for age, sex, race, education, smoking, cohort status, radiographic knee OA, co-morbidity scores, and baseline scores when available. RESULTS: Follow-up data were available for 1727 (71.9%) participants (mean age 67.9 ± 5.3 years; 61.6% female). At baseline, obese subjects compared to overweight and normal were on a greater number of medications (4.28 vs. 3.63 vs. 3.32), had lower gait speeds (1.22 vs. 1.32 vs. 1.36 m/s), higher Charlson scores (0.59 vs. 0.37 vs. 0.30), and higher Western Ontario and McMaster University OA Index (WOMAC) scores (right: 14.8 vs. 10.3 vs. 7.5; left: 14.4 vs. 9.9 vs. 7.5). SF-12 scores at 6 years were lower in obese patients than in overweight or normal [99.5 (95% CI 98.7-100.4) vs. 101.1 (95% CI 100.4-101.8) vs. 102.8 (95% CI 101.8-103.8)], as were PASE scores [115.1 (95% CI 110.3-119.8) vs. 126.2 (95% CI 122.2-130.2) vs. 131.4 (95% CI 125.8-137.0)]. The LLDI limitation component demonstrated differences in obese compared to overweight or normal [78.6 (95% CI 77.4-79.9) vs. 81.2 (95% CI 80.2-82.3) vs. 82.5 (95% CI 81.1-84.0)]. CONCLUSIONS: Obesity was associated with worse physical activity scores, lower quality of life, and higher risk of 6-year disability.

Benzocaine-induced methemoglobinemia: report of a severe reaction and review of the literature.

OBJECTIVE: To report a case of benzocaine-induced inethemoglobinemia and present a review of the related literature. CASE REPORT: An 83-year-old man received benzocaine topical anesthesia 600 mg prior to intubation for resection of a thyroid adenoma. The patient became severely cyanotic after induction of anesthesia. After a negative workup for common causes of cyanosis. blood co-oximetry analysis revealed a methemoglobin concentration of 54.1 percent. Intravenous methylene blue reversed the methemoglobinemia, although delayed recurrence 20 h later necessitated readministration of intravenous methylene blue. The patient developed cardiovascular instability and severe neurologic depression requiring prolonged ventilatory support. DISCUSSION: Methemoglobinemia can result from exposure to a number of drugs including benzocaine. Cyanosis, neurological and cardiac dysfunction may result when methemoglobin concentrations exceed 30 percent. Clinical diagnosis is made on the presentation of cyanosis unresponsive to oxygen administration and a distinctive arterial blood brown color; laboratory confirmation is by cooximetry. Treatment of symptomatic methemoglobinemia is by intravenous methylene blue (1-2 mg/kg) administration. Fifty-four cases of benzocaine-induced methemoglobinemia have been reported in the literature. Intubation, endoscopy/bronchoscopy, and ingestion were the most common procedures in which benzocaine administration produced methemoglobinemia. Infants and the elderly were more likely to develop toxic methemoglobinemia after benzocaine exposure. Other risk factors included genetic reductase deficiencies, exposure to high doses of anesthetic, and presence of denuded skin and mucous membranes. CONCLUSIONS: Because of the potential for severe complications, methemoglobinemia should be corrected promptly in compromised patients and those with toxic benzocaine concentrations. The possibility of masking symptoms during general anesthesia carries special risk of use of this agent in the preanesthesia setting.