Derangement in Nicotinamide Adenine Dinucleotide Metabolism is Observed During Acute Kidney Injury Among Male Agricultural Workers at Risk for Mesoamerican Nephropathy.

Introduction: Mesoamerican nephropathy (MeN) is a chronic kidney disease (CKD) which may be caused by recurrent acute kidney injury (AKI). We investigated urinary quinolinate-to-tryptophan ratio (Q/T), a validated marker of nicotinamide adenine dinucleotide (NAD+) biosynthesis that is elevated during ischemic and inflammatory AKI, in a sugarcane worker population in Nicaragua with high rates of MeN. Methods: Among 693 male sugarcane workers studied, we identified 45 who developed AKI during the harvest season. We matched them 1:1 based on age and job category with 2 comparison groups: (i) "no kidney injury," active sugarcane workers with serum creatinine (sCr) <1.1 mg/dl; and (ii) "CKD," individuals no longer working in sugarcane due to their CKD, who had additional 1:1 matching for sCr. We measured urine metabolites using liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) and compared Q/T and other metabolic features between the AKI and comparison groups. Results: Urine Q/T was significantly higher in workers with AKI than in those with no kidney injury (median interquartile Range [IQR]: 0.104 [0.074-0.167] vs. 0.060 [0.045-0.091], P < 0.0001) and marginally higher than in workers with CKD (0.086 [0.063-0.142], P = 0.059). Urine levels of the NAD+ precursor nicotinamide were lower in the AKI group than in comparison groups. Conclusion: Workers at risk for MeN who develop AKI demonstrate features of impaired NAD+ biosynthesis, thereby providing new insights into the metabolic mechanisms of injury in this population. Therapeutic use of oral nicotinamide, which may ameliorate NAD+ biosynthetic derangement and fortify against kidney injury, should be investigated to prevent AKI in this setting.

Factors Associated with Recent Use of Nicotine Replacement Therapy Among Multiethnic Smokers Residing in Public Housing.

Introduction: Understanding factors associated with increased use of nicotine replacement therapy (NRT) is critical to implementing cessation interventions for low-income individuals yet the factors associated with NRT use among low-income smokers are poorly understood. Aims: Assess factors associated with NRT use among low-income public housing residents. Methods: 'Kick it for Good' was a randomised smoking cessation intervention study conducted among residents of public housing sites in Boston, MA. Secondary, cross-sectional analyses were conducted on smokers from a community-based intervention cessation intervention who reported making a quit attempt and use of NRT in the past 12 months (n = 234). Results: Among smokers who made a quit attempt in the past year, 29% reported using NRT. Black (prevalence ratio,PR = 0.52, 95% CI: 0.38-0.71) and Hispanic (PR = 0.52, 95% CI: 0.31-0.88) participants were less likely to report use of NRT compared with Whites. The prevalence of recent NRT use was greatest among those both asking for and receiving provider advice (PR = 1.90, 95% CI: 0.96-3.78). Conclusions: Minority race and ethnicity and low provider engagement on NRT use were associated with lower NRT use. Providing barrier-free access to NRT and facilitating provider engagement with smokers regarding NRT use can increase NRT use among low-income populations.