Does Hormone Supplementation With Levothyroxine Improve Hypothyroid Impaired Cognitive Dysfunction?

Hyperthyroidism, which is also called overactive thyroid, is when the thyroid produces too much hormone. Symptoms include unintended weight loss, rapid or irregular heartbeat and nervousness or anxiety. Thyroid hormone is one of the most commonly prescribed medications, but taking too much comes with health risks and might even be linked to an increased risk of dementia. If you take thyroid medication, talk to your provider at least once a year about your dose. Instead, I believe that the increased risk of developing dementia in people with thyroid disease is more likely related to how well-managed their thyroid disease is. The other big requirement to be eligible for anti-amyloid therapy is evidence of amyloid in the brain.

1. Evidence Supporting the Link Between Thyroid Disease and Cognitive Impairment

One study (28) was scored 5, another (9) was scored 6, four (10, 22, 23, 27) were scored 7, four (13, 15, 21, 24) were scored 8, and seven (6, 7, 8, 11, 12, 25, 26) were scored 9. Hantavirus typically is reported in spring and summer, often due to exposures that occur when people are near mouse droppings in homes, sheds or poorly ventilated areas. Authorities linked her death to hantavirus pulmonary syndrome, a rare but potentially fatal disease spread by infected rodent droppings. Thyroid medication pills prescribed to Arakawa were found nearby and weren’t listed as contributing to her death, Jarrell said. “You are talking about very severe Alzheimer’s disease that normal people would be in a nursing home or have a nurse, but she was taking care of him until she passed away,” Baden said. Any information published on this website or by this brand is not intended as a substitute for medical advice, and you should not take any action before consulting with a healthcare professional.

Comparison with other studies

The size of the gray boxes around the point estimates reflect the weight assigned to each study. Subclinical hypothyroidism was defined as high TSH concentrations but normal blood concentrations of thyroid hormones. Subclinical hyperthyroidism was defined as low TSH concentrations but normal blood concentrations of thyroid hormones.

Goyal et al. observed significant improvement in various domains of cognition, including executive function 16. Prasanth et al. specified in their study that TSH levels correlate negatively with cognitive function and worsens as TSH levels rise 18. According to Mulat et al., TSH increases the risk of cognitive impairment by 30% for every unit rise 40.

A trial of levothyroxine replacement in subclinical hypothyroid individuals reported improvement in verbal fluency, visual and total memory scores 17-19,35,44-47. These findings are per a study that indicated increased T4 levels result in better verbal performance 12. Twenty-one hypothyroid and 17 subclinical hypothyroid patients who underwent several neuropsychological tests at baseline, 3 and 6 months were compared with normal subjects. LT-4 replacement improved verbal memory in both overt and subclinical hypothyroid patients; however, only the subclinical group restored spatial memory, while the overt group remained impaired 35. Imaging studies revealed levothyroxine’s reversible effect on cerebral blood flow, brain function, cortical excitability, and brain metabolic activity 17,28,48-50. A case report on an 81-year-old male patient with memory impairment and behavioral disturbances showed rapid improvement in neuropsychiatric symptoms after levothyroxine replacement.

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• Consistent with prior research, we also found that increasing age, minority race, and presence of at least one APOE ε4 allele each independently contribute to an increased risk of developing DAT or more rapid disease progression once diagnosed (Mortimer and Borenstein, 2006).
• Symptoms include unintended weight loss, rapid or irregular heartbeat and nervousness or anxiety.
• The development of a hypothyroid state is linked with the disease’s progression to the middle and late stages.
• The thyroid hormone has an outstanding role in neuron regulation in the adult brain.

The Best Thyroid Supplements For Weight Loss

The fT4 assay had an analytical sensitivity of 0.30 ng/dL and an intra-assay precision of 4.8% at 2.10 ng/dL. The T4 assay had an analytical sensitivity of 0.30 µg/dL and an intra-assay precision of 4.6% at 8.23 µg/dL. The baseline sample consisted of participants of the Honolulu Heart Program, a prospective cohort study carried out among Japanese-American men living on the Island of Oahu, Hawaii from 1965 onwards 30. Of the 4,676 survivors, 3,734 (80%) participated in a fourth examination between 1991 and 1993 as part of the HAAS. Between 1994–1996 and 1997–1999 two additional examinations were carried out (participation rates 84 and 75% respectively). Prevalent dementia was ascertained at examination 4 and incident dementia at examinations 5 and 6.

At the cellular level, Hyperthyroidism coexists with a lipid peroxidation state which can be inhibited by treatment of hyperthyroidism (42). In addition, liver mitochondria in the hyperthyroid state have a strong ability to scavenge H2O2, resulting in a substantial production of reactive oxygen species (ROS) and damaging redox equilibrium (43). However, these findings only demonstrate the high oxidative stress state of hyperthyroidism from peripheral tissues and do not prove whether the same mechanism applies to the central nervous system.

In the AD cases, there were no significant correlations observed between TRH and TSH, TT3, TT4, FT3, and FT4, as well as between TSH and TT3, TT4, FT3, FT4 (30). However, in the healthy controls, TRH showed significant correlations with TSH and FT4, while TSH exhibited significant correlations with TT4 and FT4 (30). This shows a severe deterioration of the biofeedback regulation of hypothalamic-pituitary-thyroid axis. Similarly, Chen et al. discovered that serum TSH levels in AD patients lacked a circadian rhythm and were significantly lower than health controls (31). In the future, a clear pathological diagnosis of hypothalamic and pituitary degeneration during disease progression in AD is needed.

TTR has been reported to function as a pro-angiogenic agent during early stage AD development by upregulating the expression of VEGF, Ang-2, IL-6 and IL-8 (33). Meanwhile, TTR can also regulate βA metabolism by inhibiting βA production, accelerating βA clearance and attenuating βA toxicity (35). Therefore, the stability of TTR function is essential for the whole pathological process of AD and plays a key neuroprotective role.

In the new study, the researchers looked at the records of around 65,000 prilosec synthroid patients in the Johns Hopkins Community Physicians Network between 2014 and 2022 who were aged 65 and older. None of the patients had a diagnosis of cognitive decline or a low TSH level within six months of their first provider visit. I’ve spent the last 8 years of my life reading, researching, and helping people with thyroid problems, hormone imbalances, and weight loss resistance. Through my articles, videos, and supplements, I’ve been fortunate enough to help thousands of people take control of their weight, thyroid, and hormones. My recommendation is to take the steps outlined above and do your best to mitigate all risk factors which are known to contribute to the development of dementia.