The impact of thyroid dysfunction on domain-specific cognitive performance: a cross-sectional study

Görkem Tutal Gürsoy; Çağatay Çopur; Kazım Karadaş

Article Details

The impact of thyroid dysfunction on domain-specific cognitive performance: a cross-sectional study

Authors:

Görkem Tutal Gürsoy | Çağatay Çopur | Kazım Karadaş

Publisher:

MediHealth Academy Yayıncılık

Main Topics:

Nöroloji ve Nöromüsküler Hastalıklar

Journal:

Journal of Medicine and Palliative Care Vol.6 Issue 3, pp.265-270

Document Type:

Article

Publication Date:

6/2025

Document Language:

English

Document ID (Org No.):

2001350895

pISSN:

2717-7505

Keywords:

Abstract:

 Aims: While thyroid dysfunction has been implicated in cognitive impairment, its domain-specific effects remain unclear. This study investigates the relationship between thyroid status and performance across distinct cognitive domains in older adults. Methods: We analyzed 166 participants 32 controls, 48 mild cognitive impairment, 86 Alzheimers disease aged 50-80 years without pre-existing thyroid conditions. Participants underwent comprehensive assessment including Mini-Mental State Exam MMSE and Clinical Dementia Rating CDR. Thyroid status was classified by TSH levels: low 0.55 μIUml, normal 0.554.78 μIUml, and high 4.78 μIUml. Data normality was evaluated using the Shapiro-Wilk test, and non-parametric methods were applied due to non-normal distributions. Spearmans correlation and Kruskal-Wallis tests were used for bivariate analyses. Chi-square tests assessed associations between thyroid status and categorical variables. A multinomial logistic regression model was employed to identify predictors of thyroid status, with the low TSH group as the reference category. To address class imbalance, the SMOTE technique was applied, and multicollinearity was examined using the variance inflation factor VIF. Results: Among the MMSE subdomains, recall, orientation, and attention and calculation were significantly associated with thyroid status. Recall was a strong predictor for both normal and high TSH levels. Orientation scores positively predicted normal TSH and negatively predicted high TSH. Attention and calculation was significantly associated only with normal TSH. Additionally, higher CDR scores were significantly linked to high TSH status. Conclusion: These findings suggest that rather than evaluating global cognition, domain-specific cognitive assessment may provide more meaningful insights into the cognitive effects of thyroid dysfunction.

 Aims: While thyroid dysfunction has been implicated in cognitive impairment, its domain-specific effects remain unclear. This study investigates the relationship between thyroid status and performance across distinct cognitive domains in older adults. Methods: We analyzed 166 participants 32 controls, 48 mild cognitive impairment, 86 Alzheimers disease aged 50-80 years without pre-existing thyroid conditions. Participants underwent comprehensive assessment including Mini-Mental State Exam MMSE and Clinical Dementia Rating CDR. Thyroid status was classified by TSH levels: low 0.55 μIUml, normal 0.554.78 μIUml, and high 4.78 μIUml. Data normality was evaluated using the Shapiro-Wilk test, and non-parametric methods were applied due to non-normal distributions. Spearmans correlation and Kruskal-Wallis tests were used for bivariate analyses. Chi-square tests assessed associations between thyroid status and categorical variables. A multinomial logistic regression model was employed to identify predictors of thyroid status, with the low TSH group as the reference category. To address class imbalance, the SMOTE technique was applied, and multicollinearity was examined using the variance inflation factor VIF. Results: Among the MMSE subdomains, recall, orientation, and attention and calculation were significantly associated with thyroid status. Recall was a strong predictor for both normal and high TSH levels. Orientation scores positively predicted normal TSH and negatively predicted high TSH. Attention and calculation was significantly associated only with normal TSH. Additionally, higher CDR scores were significantly linked to high TSH status. Conclusion: These findings suggest that rather than evaluating global cognition, domain-specific cognitive assessment may provide more meaningful insights into the cognitive effects of thyroid dysfunction.

 Aims: While thyroid dysfunction has been implicated in cognitive impairment, its domain-specific effects remain unclear. This study investigates the relationship between thyroid status and performance across distinct cognitive domains in older adults. Methods: We analyzed 166 participants 32 controls, 48 mild cognitive impairment, 86 Alzheimers disease aged 50-80 years without pre-existing thyroid conditions. Participants underwent comprehensive assessment including Mini-Mental State Exam MMSE and Clinical Dementia Rating CDR. Thyroid status was classified by TSH levels: low 0.55 μIUml, normal 0.554.78 μIUml, and high 4.78 μIUml. Data normality was evaluated using the Shapiro-Wilk test, and non-parametric methods were applied due to non-normal distributions. Spearmans correlation and Kruskal-Wallis tests were used for bivariate analyses. Chi-square tests assessed associations between thyroid status and categorical variables. A multinomial logistic regression model was employed to identify predictors of thyroid status, with the low TSH group as the reference category. To address class imbalance, the SMOTE technique was applied, and multicollinearity was examined using the variance inflation factor VIF. Results: Among the MMSE subdomains, recall, orientation, and attention and calculation were significantly associated with thyroid status. Recall was a strong predictor for both normal and high TSH levels. Orientation scores positively predicted normal TSH and negatively predicted high TSH. Attention and calculation was significantly associated only with normal TSH. Additionally, higher CDR scores were significantly linked to high TSH status. Conclusion: These findings suggest that rather than evaluating global cognition, domain-specific cognitive assessment may provide more meaningful insights into the cognitive effects of thyroid dysfunction.

 Amaç: Tiroid disfonksiyonunun bilişsel işlevler üzerindeki etkileri bilinmekle birlikte, alana özgü ilişkileri tam olarak aydınlatılamamıştır. Bu çalışma, yaşlı bireylerde tiroid fonksiyon durumu ile spesifik bilişsel alanlardaki performans arasındaki ilişkiyi incelemeyi amaçlamaktadır. Gereç ve Yöntemler: Çalışmaya, önceden tiroid hastalığı bulunmayan 50-80 yaş aralığındaki 167 birey 32 kontrol, 48 hafif bilişsel bozukluk, 86 Alzheimer hastası dahil edilmiştir. Katılımcıların Mini-Mental Durum Değerlendirmesi MMSE; yönelim, bellek, dikkathesaplama, geri çağırma ve dil ve Klinik Demans Derecelendirmesi CDR ile kapsamlı bilişsel değerlendirmeleri yapılmıştır. Tiroid fonksiyonları TSH düzeylerine göre sınıflandırılmıştır: düşük 0.55 μIUmL, normal 0.55-4.78 ve yüksek 4.78. İstatistiksel analizlerde Spearman korelasyon, Mann-Whitney U testleri ve sınıf dengesizliğini düzeltmek için SMOTE yöntemiyle çok değişkenli lojistik regresyon modelleri kullanılmıştır. Bulgular: Düşük TSH düzeyleri, bozulmuş geri çağırma performansı ile anlamlı şekilde ilişkili bulunmuştur OR 0.17, 95 GA 0.06-0.46, p0.001. Yüksek TSH düzeyleri ise yönelim ve dikkathesaplama alanlarında bozulma ile ilişkilendirilmiştir p0.001. CDR skorları ile düşük TSH arasında belirgin bir ters ilişki saptanmış olup OR 0.036, 95 GA 0.006-0.199, demans şiddeti arttıkça düşük TSH olasılığının 27.8 kat azaldığı hesaplanmıştır. Toplam MMSE skorları ve diğer bilişsel alanlarda anlamlı bir ilişki gözlenmemiştir. Sonuç: Tiroid disfonksiyonunun bilişsel işlevler üzerindeki etkileri global değil, alana özgüdür. Hipotiroidi ve hipertiroidinin farklı bilişsel alanlarda ayrışan etkileri olduğu ve tiroid fonksiyonu ile bilişsel performans arasında karmaşık muhtemelen U-şeklinde bir ilişki bulunduğu görülmüştür. Bu bulgular, tiroid bozukluklarında alana özgü bilişsel değerlendirmenin önemini vurgulamakta olup, gelecekte longitudinal çalışmalarla desteklenmesi gerekmektedir.

Article Details

The impact of thyroid dysfunction on domain-specific cognitive performance: a cross-sectional study

Authors:

Görkem Tutal Gürsoy | Çağatay Çopur | Kazım Karadaş

Publisher:

MediHealth Academy Yayıncılık

Main Topics:

Nöroloji ve Nöromüsküler Hastalıklar

Journal:

Journal of Medicine and Palliative Care Vol.6 Issue 3, pp.265-270

Document Type:

Article

Publication Date:

6/2025

Document Language:

English

Document ID (Org No.):

2001350895

pISSN:

2717-7505

Thyroid dysfunction

cognitive domains

Mini-Mental State Exam

dementia

TSH

cognitive impairmentTiroid disfonksiyonu

Bilişsel bozukluk

kognitif alanlar

minimental test

demans

Issues

Article Details

Authors: Görkem Tutal Gürsoy | Çağatay Çopur | Kazım Karadaş

Publisher: MediHealth Academy Yayıncılık

Main Topics: Nöroloji ve Nöromüsküler Hastalıklar

Journal: Journal of Medicine and Palliative Care Vol.6 Issue 3, pp.265-270

Document Type: Article

Publication Date: 6/2025

Document Language: English

Document ID (Org No.): 2001350895

pISSN: 2717-7505

Issues

Authors:

Görkem Tutal Gürsoy | Çağatay Çopur | Kazım Karadaş

Publisher:

MediHealth Academy Yayıncılık

Main Topics:

Nöroloji ve Nöromüsküler Hastalıklar

Journal:

Journal of Medicine and Palliative Care Vol.6 Issue 3, pp.265-270

Document Type:

Article

Publication Date:

6/2025

Document Language:

English

Document ID (Org No.):

2001350895

pISSN:

2717-7505