Evidence for a role of metformin in preventing olfactory dysfunction among older adults

BACKGROUND

Olfactory dysfunction (OD) is increasingly recognized as a hallmark of unhealthy aging and is intimately associated with mortality, but therapies remain elusive. Recognizing the increased prevalence of OD in individuals with diabetes, and the potential anti-aging effects of metformin, we studied the association of metformin use with OD.

METHODS

Cross-temporal study of participants from Waves 2 (2010-11) and 3 (2015-16) of the National Social Life, Health, and Aging Project (NSHAP), a nationally representative cohort study of community-dwelling older adults. We included participants with diabetes who had complete data on olfaction and relevant covariates at Wave 2 and were not lost to follow-up at Wave 3. Olfactory identification (OI), the ability to identify the odorant, and olfactory sensitivity (OS), the ability to detect the presence of an odorant, were tested. Weighted multivariable logistic regression was used to study the association between metformin use at Wave 2 (baseline) and odds of having impaired OI/OS at Wave 3, adjusted for age, sex, race/ethnicity, education, smoking, BMI, HbA1c, years since diabetes diagnosis, and insulin use.

RESULTS

Among 228 participants with diabetes (mean age=70 years, 53% female, 21% Black), 112 (49%) used metformin at baseline. Relative to nonusers, users had 58% lower odds of impaired OI and 67% lower odds of impaired OS at Wave 3. Among participants with normal baseline OS (N=62), users had 97% lower odds of impaired OS at Wave 3.

CONCLUSIONS

Metformin use is associated with lower odds of OD among individuals with diabetes, suggesting a potential protective effect on olfaction. Future work including a larger sample and additional information on metformin use is needed to establish whether these findings are independent of diabetic control.

Nonpharmacological interventions to reduce respiratory viral transmission: an evidence-based review with recommendations

BACKGROUND

Viral respiratory infections are a leading cause of worldwide mortality and exert the potential to cause global socioeconomic crises. However, inexpensive, efficacious, and rapidly deployable strategies to reduce viral transmission are increasingly important in the setting of an ongoing pandemic, though not entirely understood. This article provides a comprehensive review of commonly employed nonpharmacological interventions to interrupt viral spread and provides evidence-based recommendations for their use.

METHODOLOGY

A systematic review of three databases was performed. Studies with defined endpoints of subjects receiving one of five interventions (nasal washing, gargling, personal protective equipment (PPE), social distancing, and hand hygiene) were included. An evidence-based review of the highest level of evidence, with recommendations, was created in accordance with a previously described, rigorous, iterative process.

RESULTS

Fifty-four primary studies were included. The most commonly studied intervention was hand hygiene, followed by PPE, gargling, saline nasal washing, and social distancing.

CONCLUSIONS

Mask use and hand hygiene are strong recommendations for prevention of viral transmission. Donning gloves, gowns, and eye protection are a recommendation in healthcare settings. Saline nasal washing and gargling are options in selected populations. Although an aggregate level of evidence is not provided, the authors recommend social distancing.

Lack of impact of radiologic septal measurements upon patient symptoms and performance of septoplasty during endoscopic sinus surgery

BACKGROUND

Recent literature suggests that concurrent septoplasty during endoscopic sinus surgery (ESS) improves patient outcomes, however, the underlying indications for performing concurrent septoplasty are unknown. The objective of this study was to investigate the relationship between objective radiologic measures of nasal septal deviation with preoperative patient symptomatology and measures of CRS disease severity. We also sought to understand the association of objective radiologic measurements with surgeon performance of concurrent septoplasty during ESS.

METHODOLOGY

Seventy-four patients with CRS undergoing ESS were prospectively enrolled. Angles of septal deviation, intranasal areas and volumes were assessed on preoperative computed tomography (CT) scans and correlated with a robust battery of patient reported outcomes measures (PROMs), objective measures of CRS severity including olfaction scores, radiologic and endoscopic staging, and performance of septoplasty.

RESULTS

Intranasal areas and volumes demonstrated only weak linear associations with patient-reported nasal congestion, however, angles of septal deviation alone did not correlate with congestion or any other PROM measure. Meanwhile, radiologic septal-related measurements did not correlate with objective measures of CRS disease severity or the performance of a concurrent septoplasty.

CONCLUSIONS

Though prior studies demonstrate improved patient outcomes in the setting of concurrent septoplasty during ESS, this study failed to establish an association between preoperative radiologic septal-related measurements and patient symptomatology or surgeon decision to perform septoplasty. Although objective factors to identify patients most likely to benefit from concurrent septoplasty remain unidentified, the potential improvement of surgical recommendations and patient outcomes makes this an important area of continued investigation.