[Homocysteine, vitamin B-12, folic acid and the cognitive decline in the elderly]

Digging into the intrinsic capacity concept: Can it be applied to Alzheimer's disease?

Historically, aging research has largely centered on disease pathology rather than promoting healthy aging. The World Health Organization's (WHO) policy framework (2015-2030) underscores the significance of fostering the contributions of older individuals to their families, communities, and economies. The WHO has introduced the concept of intrinsic capacity (IC) as a key metric for healthy aging, encompassing five primary domains: locomotion, vitality, sensory, cognitive, and psychological. Past AD research, constrained by methodological limitations, has focused on single outcome measures, sidelining the complexity of the disease. Our current scientific milieu, however, is primed to adopt the IC concept. This is due to three critical considerations: (I) the decline in IC is linked to neurocognitive disorders, including AD, (II) cognition, a key component of IC, is deeply affected in AD, and (III) the cognitive decline associated with AD involves multiple factors and pathophysiological pathways. Our study explores the application of the IC concept to AD patients, offering a comprehensive model that could revolutionize the disease's diagnosis and prognosis. There is a dearth of information on the biological characteristics of IC, which are a result of complex interactions within biological systems. Employing a systems biology approach, integrating omics technologies, could aid in unraveling these interactions and understanding IC from a holistic viewpoint. This comprehensive analysis of IC could be leveraged in clinical settings, equipping healthcare providers to assess AD patients' health status more effectively and devise personalized therapeutic interventions in accordance with the precision medicine paradigm. We aimed to determine whether the IC concept could be extended from older individuals to patients with AD, thereby presenting a model that could significantly enhance the diagnosis and prognosis of this disease.

Elevated Homocysteine Levels and Hypertension Relate to Cognitive Impairment via Increased White Matter Hyperintensity Volume

BACKGROUND

Recent studies have identified a relationship between elevated homocysteine levels and hypertension (HTN) with Alzheimer's disease (AD), but its pathogenesis remains unclear.

OBJECTIVE

To evaluate elevated homocysteine levels and HTN as risk factors for cognitive impairment (CI) and determine their relationship with white matter hyperintensity (WMH) volume.

METHODS

A total of 521 subjects were selected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database and divided into two groups according to the diagnostic criteria of the ADNI database. The CI group included 370 subjects, consisting of 122 with AD and 248 with mild CI, while the cognitively normal (CN) group contained 151 subjects. The history of HTN, homocysteine levels, WMH volume and Mini-Mental State Examination (MMSE) scores were analyzed.

RESULTS

The study found that patients with CI had higher homocysteine levels than those with CN. Additionally, WMH volume was significantly correlated with homocysteine levels in CI patients, and MMSE scores decreased as WMH volume increased. Further analysis revealed that CI patients with HTN had significantly higher homocysteine levels than those without HTN. Furthermore, the correlation between WMH volume and homocysteine levels was significant only in CI patients with HTN and not in those without HTN. In CN patients, there was no correlation between WMH volume and homocysteine levels in either the HTN or non-HTN groups, and no difference was observed in homocysteine levels.

CONCLUSIONS

It is indicated that elevated homocysteine levels in conjunction with HTN are associated with the increased volume of WMHs and CI.

Major Polymorphisms of Genes Involved in Homocysteine Metabolism in Malaria Patients in Ouagadougou, Burkina Faso

This study analyzed the four main polymorphisms of the genes in homocysteine metabolism in malaria patients. Forty-two randomly selected subjects, diagnosed positive for Plasmodium falciparum, were included. The four genotypes were detected by real-time PCR using the MTHFR 677C>T, MTHFR 1298A>C, MTR 2756A>G, and MTRR 66A>G detection kit (Sacace Biotechnologies REF: T01002-96-S). The results revealed frequencies of 90% 677CC, 10% 677CT, and 00% 677TT for MTHFR C677T; 78.6% 1298AA, 19% 1298AC, and 2.4% 1298CC for MTHFR A1298C; 61.9% 2756AA, 33.3% 2756AG, and 4.8% 2756GG for MTR A2756G; and 50% of 66AA, 45% of 66AG, and 5% of 66GG for MTRR A66G. Correlations were found between A2756G MTR genotypes and parasitaemia (P = 0.02), MTRR A66G and hemoglobin genotypes (P = 0.009), and MTHFR A1298C and sex (P = 0.01). This study demonstrated for the first time an association between the A2756G MTR alleles and Plasmodium falciparum malaria in Burkina Faso and gave an overview of the genotypic distribution of the major SNPs influencing the metabolism of homocysteine.