Association of Polygenic Risk Scores for Hearing Difficulty in Older Adults With Hearing Loss in Mid-Childhood and Midlife: A Population-Based Cross-sectional Study Within the Longitudinal Study of Australian Children

Polygenic Risk Score Modifies the Association of HbA1c With Hearing Loss in Middle-Aged and Older Chinese Individuals: The Dongfeng-Tongji Cohort

OBJECTIVE

Evidence regarding the modifying effect of the polygenic risk score (PRS) on the associations between glycemic traits and hearing loss (HL) was lacking. We aimed to examine whether these associations can be influenced by genetic susceptibility.

RESEARCH DESIGN AND METHODS

This cross-sectional study included 13,275 participants aged 64.9 years from the Dongfeng-Tongji cohort. HL was defined according to a pure tone average >25 dB in the better ear and further classified by severity. Prediabetes and type 2 diabetes (T2D) were defined based on the 2013 criteria from the American Diabetes Association. A PRS was derived from 37 single nucleotide polymorphisms associated with HL. Multivariable logistic regression models were fitted to estimate the associations of PRS and glycemic traits with HL and its severity.

RESULTS

Elevated fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), and T2D were positively associated with higher HL risks and its severity, with odds ratios (ORs) ranging from 1.04 (95% CI 1.00, 1.08) to 1.25 (95% CI 1.06, 1.46). We also found significant interaction between HbA1c and PRS on risks of overall HL and its severity (P for multiplicative interaction <0.05), and the effects of HbA1c on HL risks were significant only in the group with high PRS. Additionally, compared with normoglycemia in the group with low PRS, T2D was associated with an OR of up to 2.00 and 2.40 for overall HL and moderate to severe HL, respectively, in the group with high PRS (P for additive interaction <0.05).

CONCLUSIONS

PRS modifies the association of HbA1c with HL prevalence among middle-aged and older Chinese individuals.

Combined genetic polymorphisms of the GSTT1 and NRF2 genes increase susceptibility to cisplatin-induced ototoxicity: A preliminary study

OBJECTIVE

The genotype-phenotype relationship in cisplatin-induced ototoxicity remains unclear. By assessing early shifts in distortion product otoacoustic emission (DPOAE) levels after initial cisplatin administration, we aimed to discriminate patients' susceptibility to cisplatin-induced ototoxicity and elucidate their genetic background.

STUDY DESIGN

A prospective cross-sectional study.

SETTING

Tertiary referral hospital in Japan.

PATIENTS

Twenty-six patients with head and neck cancer were undergoing chemoradiotherapy with three cycles of 100 mg/m2 cisplatin.

INTERVENTIONS

Repetitive pure-tone audiometry and DPOAE measurements, and blood sampling for DNA extraction were performed. Patients were grouped into early ototoxicity presence or absence based on whether DPOAE level shifts exceeded the corresponding reference limits of the 21-day test interval.

MAIN OUTCOME MEASURES

Hearing thresholds after each cisplatin cycle, severity of other adverse events, and polymorphisms in cisplatin-induced ototoxicity-associated genes were compared.

RESULTS

Early ototoxicity was present in 14 and absent in 12 patients. Ototoxicity presence on DPOAEs was associated with greater progression of hearing loss in frequencies ≥2 kHz throughout therapy and with higher ototoxicity grades compared with ototoxicity absence. Ototoxicity was further associated with grade ≥2 nausea. Ototoxicity presence was genetically associated with the GSTT1 null genotype and G-allele of NFE2L2 rs6721961, whereas ototoxicity absence was associated with the GSTM1 null genotype. Dose-dependent progression of hearing loss was the greatest in the combined genotype pattern of GSTT1 null and the T/G or G/G variants of rs6721961.

CONCLUSION

Early DPOAE changes reflected genetic vulnerability to cisplatin-induced ototoxicity. Hereditary insufficiency of the antioxidant defense system causes severe cisplatin-induced hearing loss and nausea.

Association between genetic risk and adherence to healthy lifestyle for developing age-related hearing loss

BACKGROUND

Previous studies have shown that lifestyle/environmental factors could accelerate the development of age-related hearing loss (ARHL). However, there has not yet been a study investigating the joint association among genetics, lifestyle/environmental factors, and adherence to healthy lifestyle for risk of ARHL. We aimed to assess the association between ARHL genetic variants, lifestyle/environmental factors, and adherence to healthy lifestyle as pertains to risk of ARHL.

METHODS

This case-control study included 376,464 European individuals aged 40 to 69 years, enrolled between 2006 and 2010 in the UK Biobank (UKBB). As a replication set, we also included a total of 26,523 individuals considered of European ancestry and 9834 individuals considered of African-American ancestry through the Penn Medicine Biobank (PMBB). The polygenic risk score (PRS) for ARHL was derived from a sensorineural hearing loss genome-wide association study from the FinnGen Consortium and categorized as low, intermediate, high, and very high. We selected lifestyle/environmental factors that have been previously studied in association with hearing loss. A composite healthy lifestyle score was determined using seven selected lifestyle behaviors and one environmental factor.

RESULTS

Of the 376,464 participants, 87,066 (23.1%) cases belonged to the ARHL group, and 289,398 (76.9%) individuals comprised the control group in the UKBB. A very high PRS for ARHL had a 49% higher risk of ARHL than those with low PRS (adjusted OR, 1.49; 95% CI, 1.36-1.62; P < .001), which was replicated in the PMBB cohort. A very poor lifestyle was also associated with risk of ARHL (adjusted OR, 3.03; 95% CI, 2.75-3.35; P < .001). These risk factors showed joint effects with the risk of ARHL. Conversely, adherence to healthy lifestyle in relation to hearing mostly attenuated the risk of ARHL even in individuals with very high PRS (adjusted OR, 0.21; 95% CI, 0.09-0.52; P < .001).

CONCLUSIONS

Our findings of this study demonstrated a significant joint association between genetic and lifestyle factors regarding ARHL. In addition, our analysis suggested that lifestyle adherence in individuals with high genetic risk could reduce the risk of ARHL.