@article {9157, title = {Longitudinal Associations of Plasma TMAO and Related Metabolites with Cognitive Impairment and Dementia in Older Adults: The Cardiovascular Health Study.}, journal = {J Alzheimers Dis}, year = {2022}, month = {2022 Sep 02}, abstract = {

BACKGROUND: Animal studies suggest that gut microbiome metabolites such as trimethylamine N-oxide (TMAO) may influence cognitive function and dementia risk. However potential health effects of TMAO and related metabolites remain unclear.

OBJECTIVE: We examined prospective associations of TMAO, γ-butyrobetaine, crotonobetaine, carnitine, choline, and betaine with risk of cognitive impairment and dementia among older adults aged 65 years and older in the Cardiovascular Health Study (CHS).

METHODS: TMAO and metabolites were measured in stored plasma specimens collected at baseline. Incident cognitive impairment was assessed using the 100-point Modified Mini-Mental State Examination administered serially up to 7 times. Clinical dementia was identified using neuropsychological tests adjudicated by CHS Cognition Study investigators, and by ICD-9 codes from linked Medicare data. Associations of each metabolite with cognitive outcomes were assessed using Cox proportional hazards models.

RESULTS: Over a median of 13 years of follow-up, 529 cases of cognitive impairment, and 522 of dementia were identified. After multivariable adjustment for relevant risk factors, no associations were seen with TMAO, carnitine, choline, or betaine. In contrast, higher crotonobetaine was associated with 20-32\% higher risk of cognitive impairment and dementia per interquintile range (IQR), while γ-butyrobetaine was associated with \~{}25\% lower risk of the same cognitive outcomes per IQR.||Conclusion:These findings suggest that γ-butyrobetaine, crotonobetaine, two gut microbe and host metabolites, are associated with risk of cognitive impairment and dementia. Our results indicate a need for mechanistic studies evaluating potential effects of these metabolites, and their interconversion on brain health, especially later in life.

}, issn = {1875-8908}, doi = {10.3233/JAD-220477}, author = {de Oliveira Otto, Marcia C and Li, Xinmin S and Wang, Zeneng and Siscovick, David and Newman, Anne B and Lai, Heidi Tsz Mung and Nemet, Ina and Lee, Yujin and Wang, Meng and Fretts, Amanda and Lemaitre, Rozenn N and Tang, W H Wilson and Lopez, Oscar and Hazen, Stanley L and Mozaffarian, Dariush} } @article {9648, title = {The Gut Microbial Metabolite Trimethylamine N-oxide, Incident CKD, and Kidney Function Decline.}, journal = {J Am Soc Nephrol}, year = {2024}, month = {2024 Apr 09}, abstract = {

BACKGROUND: Trimethylamine N-oxide (TMAO) is a gut microbiota-derived metabolite of dietary phosphatidylcholine and carnitine. Experimentally, TMAO causes kidney injury and tubulointerstitial fibrosis. Little is known about prospective associations between TMAO and kidney outcomes, especially incident CKD. We hypothesized that higher plasma TMAO levels would be associated with higher risk of incident CKD and greater rate of kidney function decline.

METHODS: We included 10,564 participants from two community-based, prospective cohorts with estimated glomerular filtration rate (eGFR) >= 60 mL/min/1.73m2 to assess incident CKD. TMAO was measured using targeted mass spectrometry at baseline and one follow-up visit. Creatinine and Cystatin C were measured up to 4 times during follow-up and used to compute eGFR. Incident CKD was defined as an eGFR decline >= 30\% from baseline and a resulting eGFR<60 ml/min/1.73 m2. Time-varying Cox models assessed the association of serial TMAO measures with incident CKD, adjusting for sociodemographic, lifestyle, diet, and cardiovascular disease risk factors. Linear mixed models assessed the association with annualized eGFR change in 10,009 participants with at least one follow-up eGFR measure without exclusions for baseline eGFR levels.

RESULTS: During a median follow-up of 9.4 years (interquartile range: 9.1-11.6 years), 979 incident CKD events occurred. Higher TMAO levels associated with higher risk of incident CKD (2nd to 5th vs. 1st quintile HR[95\%CI]= 1.65 [1.22-2.23], 1.68 [1.26-2.25], 2.28 [1.72-3.02], and 2.24[1.68-2.98], respectively) and greater annualized eGFR decline ( 2nd to 5th vs. 1st quintile annualized eGFR change= -0.21 [-0.32, -0.09], -0.17 [-0.29, -0.05], -0.35 [-0.47, -0.22], and -0.43[-0.56, -0.30], respectively) with monotonic dose-response relationships. These associations were consistent across different racial/ethnic groups examined. The association with eGFR decline was similar to or larger than that seen for established CKD risk factors including diabetes, per 10 mmHg of higher systolic blood pressure, per 10 years of older age, and Black race.

CONCLUSIONS: In community-based US adults, higher serial measures of plasma TMAO were associated with higher risk of incident CKD and greater annualized kidney function decline.

}, issn = {1533-3450}, doi = {10.1681/ASN.0000000000000344}, author = {Wang, Meng and Tang, W H Wilson and Li, Xinmin S and de Oliveira Otto, Marcia C and Lee, Yujin and Lemaitre, Rozenn N and Fretts, Amanda and Nemet, Ina and Sotoodehnia, Nona and Sitlani, Colleen M and Budoff, Matthew and DiDonato, Joseph A and Wang, Zeneng and Bansal, Nisha and Shlipak, Michael G and Psaty, Bruce M and Siscovick, David S and Sarnak, Mark J and Mozaffarian, Dariush and Hazen, Stanley L} }