Increased atherogenic index in the general hearing loss population

The Association between Serum Lipid Levels and Tinnitus Prevalence and Severity in Korean Elderly: A Nationwide Population-Based Cross-Sectional Study

PURPOSE

We aimed to investigate the association between serum lipid level and tinnitus risk in Korean older adults.

MATERIALS AND METHODS

This study used data from the 2016-2018 Korea National Health and Nutrition Examination Survey. Overall, 6021 subjects aged ≥60 years were included. Hypertriglyceridemia was defined as a serum triglyceride level of ≥200 mg/dL. The high-risk threshold of the total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-C) ratio was defined as above 5.0. The presence of tinnitus was assessed via health interviews. Tinnitus severity was classified as "not annoying," "irritating," and "severely annoying and causing sleep problems." Multivariate logistic regression analysis was performed to examine the association between serum lipid level and tinnitus risk.

RESULTS

The odds ratio (OR) of tinnitus was 1.27-times higher in the group with hypertriglyceridemia than in the group without hypertriglyceridemia after adjusting for age, sex, hypertension, diabetes, dyslipidemia, anemia, current smoking, obesity, noise exposure, stress cognition, and depressive mood or anxiety [95% confidence interval (CI) 1.04-1.56, p=0.022]. The OR of tinnitus was 1.21-times higher in the group with a high TC/HDL-C ratio than in the group without a high TC/HDL-C ratio after adjusting for the same variables as above (95% CI 1.02-1.44, p=0.025).

CONCLUSION

This study revealed that hypertriglyceridemia and high TC/HDL-C ratio were significantly associated with an increased OR of tinnitus in Korean older adults.

The Value of Plasma Atherogenic Index in Prognosis of Sudden Hearing Loss

BACKGROUND

The impact of lipid parameters on hearing loss has been extensively studied in the literature. However, there is currently no study investigating the prognostic factor of plasma atherogenic index in patients with sudden hearing loss. This study aimed to evaluate the relationship of plasma atherogenic index in patients with sudden hearing loss.

METHODS

Plasma atherogenic index is calculated using the logarithmic ratio of triglycerides [mg/dL] to high-density lipoprotein cholesterol ([mg/dL]) based on lipid parameters. The patients were divided into tertiles according to their plasma atherogenic index values and the role of plasma atherogenic index on prognosis was investigated among the tertiles. The difference between baseline and control audiometer values for each patient was calculated, and a linear regression analysis was used to determine its statistical significance.

RESULTS

A total of 84 sudden hearing loss patients (57 male: 68%; 27 female: 32%) were included in the study. The mean age of the study participants was 45.3 ± 14.0. There was an inverse relationship between plasma atherogenic index and difference of audiometer values. Linear regression analyses revealed odds ratio and 95% confidence intervals of 0.405 (0.123-1.331) with P=.135 for 500 Hz, 0.371 (0.071-0.990) with P=.048 for 1000 Hz, 0.319 (0.119-0.851) with P=.024 for 2000 Hz and 0.406 (0.161-0.992) with P=.049 for 4000 Hz.

CONCLUSION

To the best of our knowledge, this is the first study to demonstrate that plasma atherogenic index can serve as an indicator of a poor prognosis in the treatment of sudden hearing loss.

Atherogenic index predicts all-cause and cardiovascular mortality in incident peritoneal dialysis patients

BACKGROUND AND AIMS

Atherosclerosis, the main cause of cardiovascular disease (CVD), is prevalent in patients undergoing peritoneal dialysis (PD). Atherogenic index (AI) is a strong predictor of atherosclerosis. However, its prognostic value in CVD outcomes and all-cause mortality among patients undergoing PD remains uncertain. Therefore, we aimed to evaluate the association between AI and all-cause and CVD mortality in PD patients.

METHODS

Calculated based on lipid profiles obtained through standard laboratory procedures, AI was evaluated in 2682 patients who underwent PD therapy between January 2006 and December 2017 and were followed up until December 2018. The study population was divided into four groups according to the quartile distribution of AI (Q1: <2.20, Q2: 2.20 to <2.97, Q3: 2.97 to <4.04, and Q4: ≥4.04). Multivariable Cox models were employed to explore the associations between AI and CVD and all-cause mortality was evaluated.

RESULTS

During a median follow-up of 35.5 months (interquartile range, 20.9-57.2 months), 800 patients died, including 416 deaths from CVD. Restricted cubic splines showed non-linear relationship between AI and adverse clinical outcomes. The risks of all-cause and CVD mortality gradually increased across quartiles (log-rank, p < 0.001). After adjusting for potential confounders, the highest quartile (Q4) showed significantly elevated hazard ratio (HR) for both all-cause mortality (HR 1.54 [95% confidence interval (CI), 1.21-1.96]) and CVD mortality risk (HR 1.78 [95% CI, 1.26-2.52]), compared to the lowest quartile (Q1).

CONCLUSIONS

AI was independently associated with all-cause and CVD mortality in patients undergoing PD, suggesting that AI might be a useful prognostic marker.

Tobacco, but Neither Cannabis Smoking Nor Co-Drug Use, Is Associated With Hearing Loss in the National Health and Nutrition Examination Survey, 2011 to 2012 and 2015 to 2016

INTRODUCTION

A relationship between tobacco smoking and hearing loss has been reported; associations with cannabis smoking are unknown. In this cross-sectional population-based study, we examined relationships between hearing loss and smoking (tobacco, cannabis, or co-drug use).

METHODS

We explored the relationship between hearing loss and smoking among 2705 participants [mean age = 39.41 (SE: 0.36) years] in the National Health and Nutrition Examination Survey (2011 to 12; 2015 to 16). Smoking status was obtained via questionnaire; four mutually exclusive groups were defined: nonsmokers, current regular cannabis smokers, current regular tobacco smokers, and co-drug users. Hearing sensitivity (0.5 to 8 kHz) was assessed, and two puretone averages (PTAs) computed: low- (PTA 0.5,1,2 ) and high-frequency (PTA 3,4,6,8 ). We defined hearing loss as threshold >15 dB HL. Multivariable logistic regression was used to examine sex-specific associations between smoking and hearing loss in the poorer ear (selected based on PTA 0.5,1,2 ) adjusting for age, sex, race/ethnicity, hypertension, diabetes, education, and noise exposure with sample weights applied.

RESULTS

In the age-sex adjusted model, tobacco smokers had increased odds of low- and high-frequency hearing loss compared with non-smokers [odds ratio (OR) = 1.58, 95% confidence ratio (CI): 1.05 to 2.37 and OR = 1.97, 95% CI: 1.58 to 2.45, respectively]. Co-drug users also had greater odds of low- and high-frequency hearing loss [OR = 2.07, 95% CI: 1.10 to 3.91 and OR = 2.24, 95% CI: 1.27 to 3.96, respectively]. In the fully adjusted multivariable model, compared with non-smokers, tobacco smokers had greater odds of high-frequency hearing loss [multivariable adjusted odds ratio = 1.64, 95% CI: 1.28-2.09]. However, in the fully adjusted model, there were no statistically significant relationships between hearing loss (PTA 0.5,1,2 or PTA 3,4,6,8 ) and cannabis smoking or co-drug use.

DISCUSSION

Cannabis smoking without concomitant tobacco consumption is not associated with hearing loss. However, sole use of cannabis was relatively rare and the prevalence of hearing loss in this population was low, limiting generalizability of the results. This study suggests that tobacco smoking may be a risk factor for hearing loss but does not support an association between hearing loss and cannabis smoking. More definitive evidence could be derived using physiological measures of auditory function in smokers and from longitudinal studies.

The G2A Receptor Deficiency Aggravates Atherosclerosis in Rats by Regulating Macrophages and Lipid Metabolism

The orphan G protein-coupled receptor G2A has been linked to atherosclerosis development. However, available data from mouse models are controversial. Rat G2A receptor bears more similarities with its human homolog. We proposed that the atherosclerosis model established from Ldlr^–/– rat, which has been reported to share more similar phenotypes with the human disease, may help to further understand this lipid receptor. G2A deletion was found markedly aggravated in the lipid disorder in the rat model, which has not been reported in mouse studies. Examination of aortas revealed exacerbated atherosclerotic plaques in G2A deficient rats, together with increased oxidative stress and macrophage accumulation. In addition, consistently promoted migration and apoptosis were noticed in G2A deficient macrophages, even in macrophages from G2A single knockout rats. Further analysis found significantly declined phosphorylation of PI3 kinase (PI3K) and AKT, together with reduced downstream genes Bcl2 and Bcl-xl, suggesting possible involvement of PI3K/AKT pathway in G2A regulation to macrophage apoptosis. These data indicate that G2A modulates atherosclerosis by regulating lipid metabolism and macrophage migration and apoptosis. Our study provides a new understanding of the role of G2A in atherosclerosis, supporting it as a potential therapeutic target.