Ole Hoffstad

Potential Association Between the Oral Tetracycline Class of Antimicrobials Used to Treat Acne and Inflammatory Bowel Disease

OBJECTIVES:Previous studies have shown an association between isotretinoin and inflammatory bowel disease (IBD). The majority of patients prescribed isotretinoin for their acne are previously on an extended course of antibiotics. Therefore, it is important to consider antibiotic use as a confounding variable for the development of IBD.METHODS:We performed a retrospective cohort study using The Health Improvement Network database of the United Kingdom. We identified 94,487 individuals with acne who were followed up by a general practitioner for 406,294 person-years.RESULTS:>A prescription for minocycline was received by 24,085 individuals, for tetracycline/oxytetracycline by 38,603 individuals, and doxycycline by 15,032 individuals. IBD was noted in 41 individuals exposed to minocycline, 79 individuals exposed to tetracycline/oxytetracycline, 32 individuals exposed to doxycycline, and 55 (0.11%) individuals not exposed to any of these antibiotics. The hazard ratio (HR) for developing IBD for any exposure to a tetracycline antibiotic was 1.39 (1.02, 1.90). HRs for individual antibiotics were 1.19 (0.79, 1.79) for minocycline, 1.43 (1.02, 2.02) for tetracycline/oxytetracycline, and 1.63 (1.05, 2.52) for doxycycline. For ulcerative colitis, the associations (HR) were 1.10 (0.76, 1.82) for minocycline, 1.27 (0.78, 2.07) for tetracycline/oxytetracycline, and 1.06 (0.53, 2.13) for doxycycline. For Crohns disease (CD), the associations (HR) were 1.28 (0.72, 2.30) for minocycline, 1.61 (0.995, 2.63) for tetracycline/oxytetracycline, and 2.25 (1.27 4.00) for doxycycline.CONCLUSIONS:Tetracycline class antibiotics, and particularly doxycycline use may be associated with the development of IBD, particularly CD. Potential confounding by previous doxycycline exposure should be considered when assessing whether treatment with other acne medications increases the risk of IBD.

Lack of association between exposure to topical calcineurin inhibitors and skin cancer in adults.

Background: Two topical calcineurin inhibitors (TCI) are available for the treatment of atopic dermatitis and there has been concern that their use could be associated with an increased risk of nonmelanoma skin cancer (NMSC). Objective: To determine if TCI exposure is associated with an increased risk of NMSC in adults. Methods: A case-control study using a questionnaire mailed to 5,000 adults with dermatitis. Results: We received responses from 70.7% of those surveyed by mail. Overall, 25.7% reported exposure to TCI. TCI exposure was 14.4% for the cases and 30.7% for the controls. Our primary analysis was a comparison between those with NMSC and those without. The unadjusted odds ratio was 0.38 (0.31–0.47) and the adjusted (age, gender, previous NMSC, history of atopic dermatitis) was 0.54 (0.41–0.69). The odds ratio of association for NMSC decreased as the number of tubes used and the potency of the agent increased. Conclusion: This early study shows that TCI use is not associated with an increased risk of NMSC in adults.

Diabetic neuropathic foot ulcers and amputation.

A neuropathic foot ulcer is a severe complication of diabetes that can result in a more severe complication, a lower extremity amputation. We conducted a cohort study of 24,616 individuals with a diabetic neuropathic foot ulcer treated within a multicenter wound care network. A total of 1653 (6.7%) individuals had an amputation and 46.3% of these amputations were of a toe or ray (minor amputation). In the more than 10‐year follow‐up period that we studied, the percentage of those who had an amputation varied between 5.6% and 8.4%. Of those who had an amputation, the percentage that had a minor amputation increased over time from 4.0% in the earliest years to more than 60% in the later years of observation. The single most important determinant of amputation was the observation of fascia, tendon, and bone at the initial assessment. In conclusion, about 7% of those with a diabetic neuropathic foot ulcer will have an amputation and in the past 10 years there has been a remarkable increase in the number of minor as compared to major amputations.

The persistence of atopic dermatitis and filaggrin (FLG) mutations in a US longitudinal cohort.

BACKGROUND Atopic dermatitis (AD) is a common skin disease that is characterized by recurrent episodes of itching. Filaggrin (FLG) loss-of-function (FLG null) mutations have been associated with an increased risk of AD. OBJECTIVE We sought to evaluate the effect of individual FLG null mutations on the persistence of AD over time. METHODS We evaluated a multiyear prospective cohort study of children with AD with respect to FLG null mutations (R501X, 2282del4, R2447X, and S3247X). We evaluated the association of these mutations with the persistence of AD symptoms over time with respect to reports of no symptoms of AD and whether topical medication was needed for symptom resolution. RESULTS Eight hundred fifty-seven subjects were followed for 3684 person-years. One or more FLG null mutations were noted in 16.3% of subjects and specifically in 27.5% of white subjects and 5.8% of African American subjects. Subjects with an FLG null mutation were less likely (odds ratio [OR], 0.54; 95% CI, 0.41-0.71) to report that their skin was symptom free at any time compared with those without an FLG null mutation. The effect of these mutations was similar in white subjects (OR, 0.42; 95% CI, 0.31-0.57) and African-American subjects (OR, 0.53; 95% CI, 0.25-1.12; P = .62). Children with the R501X mutation (OR, 0.44; 95% CI, 0.22-0.88) were the least responsive to therapy. CONCLUSIONS In a US cohort with AD, FLG null mutations were common. Children with FLG null mutations were more likely to have persistent AD. Although these mutations were more common in those of European ancestry, their effect on persistence was similar in those of African ancestry. Response to therapy was not uniform among children with FLG null mutations.

Persistence of Mild to Moderate Atopic Dermatitis

IMPORTANCE Atopic dermatitis (AD) is a common illness of childhood. OBJECTIVE To evaluate the natural history of AD and determine the persistence of symptoms over time. DESIGN, SETTING, AND PARTICIPANTS A cross-sectional and cohort study of a nation-wide long-term registry of children with AD enrolled in the Pediatric Eczema Elective Registry (PEER). MAIN OUTCOMES AND MEASURES Self-reported outcome of whether a childs skin was AD symptom-free for 6 months at 6-month intervals. RESULTS A total of 7157 patients were enrolled in the PEER study for a total of 22,550 person-years. At least 2 years of follow-up were observed for 4248 children and at least 5 years of follow-up were observed for 2416 children. Multiple demographic and exposure variables were associated with more persistent AD. At every age (ie, 2-26 years), more than 80% of PEER participants had symptoms of AD and/or were using medication to treat their AD. It was not until age 20 years that 50% of patients had at least 1 lifetime 6-month symptom- and treatment-free period. CONCLUSIONS AND RELEVANCE Based on this large longitudinal cohort study, symptoms associated with AD seem to persist well into the second decade of a childs life and likely longer. Atopic dermatitis is probably a life-long illness.

Association between serious ischemic cardiac outcomes and medications used to treat diabetes

Data on cardiovascular outcomes among treated diabetics have been inconsistent. Our goal was to compare cardiovascular outcomes associated with different treatments for diabetes.

Location, Location, Location: Geographic Clustering of Lower-Extremity Amputation Among Medicare Beneficiaries With Diabetes

OBJECTIVE Lower-extremity amputation (LEA) is common among persons with diabetes. The goal of this study was to identify geographic variation and the influence of location on the incidence of LEA among U.S. Medicare beneficiaries with diabetes. RESEARCH DESIGN AND METHODS We conducted a cohort study of beneficiaries of Medicare. The geographic unit of analysis was hospital referral regions (HRRs). Tests of spatial autocorrelation and geographically weighted regression were used to evaluate the incidence of LEA by HRRs as a function of geographic location in the U.S. Evaluated covariates covered sociodemographic factors, risk factors for LEA, diabetes severity, provider access, and cost of care. RESULTS Among persons with diabetes, the annual incidence per 1,000 of LEA was 5.0 in 2006, 4.6 in 2007, and 4.5 in 2008 and varied by the HRR. The incidence of LEA was highly concentrated in neighboring HRRs. High rates of LEA clustered in contiguous portions of Texas, Oklahoma, Louisiana, Arkansas, and Mississippi. Accounting for geographic location greatly improved our ability to understand the variability in LEA. Additionally, covariates associated with LEA per HRR included socioeconomic status, prevalence of African Americans, age, diabetes, and mortality rate associated with having a foot ulcer. CONCLUSIONS There is profound “region-correlated” variation in the rate of LEA among Medicare beneficiaries with diabetes. In other words, location matters and whereas the likelihood of an amputation varies dramatically across the U.S. overall, neighboring locations have unexpectedly similar amputation rates, some being uniformly high and others uniformly low.

Effectiveness of recombinant human platelet-derived growth factor for the treatment of diabetic neuropathic foot ulcers.

The goal of this study was to estimate the effectiveness in actual clinical practice of recombinant human platelet‐derived growth factor (rhPDGF) for the treatment of diabetic neuropathic foot ulcer (DNFU). Previously published pivotal trials have shown that by the 20th week of care 35 percent more ulcers healed in the group randomized to receive rhPDGF than those who did not receive rhPDGF (i.e., a relative risk [RR] of about 1.35). This represents an estimate of the efficacy of rhPDGF under the tightly controlled conditions of randomized clinical trials. Treatment effectiveness under standard clinical practice was estimated in a retrospective cohort study, controlling for treatment selection bias using propensity scores. We noted 24,898 individuals with a DNFU, of whom 9.6 percent received rhPDGF. We successfully created a propensity score model that evenly balanced many wound characteristics between those who received rhPDGF and those who did not. We created five groups, which varied from those least likely to receive rhPDGF to those most likely to receive rhPDGF. The RR, controlling for the propensity, to receive rhPDGF for a healed wound after treatment with rhPDGF as compared with standard care was 1.32 (1.22, 1.38). With respect to amputation, the RR for undergoing amputation after receiving rhPDGF was 0.65 (0.54, 0.78) as compared with those who did not receive rhPDGF. Within the limitations of our study, rhPDGF is more effective than standard therapy in both helping a wound to heal and preventing amputation, and its effect is similar to the efficacy estimates from previously published randomized controlled trials.

Lack of Effectiveness of Hyperbaric Oxygen Therapy for the Treatment of Diabetic Foot Ulcer and the Prevention of Amputation: A cohort study

OBJECTIVE Hyperbaric oxygen (HBO) is a device that is used to treat foot ulcers. The study goal was to compare the effectiveness of HBO with other conventional therapies administered in a wound care network for the treatment of a diabetic foot ulcer and prevention of lower-extremity amputation. RESEARCH DESIGN AND METHODS This was a longitudinal observational cohort study. To address treatment selection bias, we used propensity scores to determine the “propensity” that an individual was selected to receive HBO. RESULTS We studied 6,259 individuals with diabetes, adequate lower limb arterial perfusion, and foot ulcer extending through the dermis, representing 767,060 person-days of wound care. In the propensity score–adjusted models, individuals receiving HBO were less likely to have healing of their foot ulcer (hazard ratio 0.68 [95% CI 0.63–0.73]) and more likely to have an amputation (2.37 [1.84–3.04]). Additional analyses, including the use of an instrumental variable, were conducted to assess the robustness of our results to unmeasured confounding. HBO was not found to improve the likelihood that a wound might heal or to decrease the likelihood of amputation in any of these analyses. CONCLUSIONS Use of HBO neither improved the likelihood that a wound would heal nor prevented amputation in a cohort of patients defined by Centers for Medicare and Medicaid Services eligibility criteria. The usefulness of HBO in the treatment of diabetic foot ulcers needs to be reevaluated.

Healing diabetic neuropathic foot ulcers: are we getting better?

Aim  To benchmark by year the likelihood that an individual with a diabetic neuropathic foot ulcer will heal over more than a 10‐year period.