Does arterial hypertension influence the onset of Huntington's disease?

Modifiable factors associated with Huntington's disease progression in presymptomatic participants

OBJECTIVE

Huntington's disease (HD) is a neurodegenerative disorder characterized by progressive motor, cognitive, and psychiatric symptoms. Our aim here was to identify factors that can be modified to slow disease progression even before the first symptoms appear.

METHODS

We included 2636 presymptomatic individuals (comparison with family controls) drawn from the prospective observational cohort Enroll-HD, with more than 35 CAG repeats and at least two assessments of disease progression measured with the composite Huntington's disease rating Scale (cUHDRS). The association between sociodemographic factors, health behaviors, health history, and cUHDRS trajectory was assessed with a mixed-effects random forest using partial dependence plots and Shapley additive explanation method.

RESULTS

Participants were followed by an average of 3.4 (SD = 1.97) years. We confirmed the negative impact of age and a high number of CAG repeats. We found that a high level of education, a body mass index (BMI) <23 kg/m2 before the age of 40 and >23 kg/m2 thereafter, alcohol consumption of <15 units per week, current coffee consumption and no smoking were linked to slow disease progression, as did no previous exposure to antidepressants or anxiolytic, no psychiatric history or comorbidities, and being female. Other comorbidities or marital status showed no major association with HD evolution.

INTERPRETATION

Reducing modifiable risk factors for HD is one way to support the presymptomatic population. A high level of education, low-to-moderate alcohol consumption, no smoking, and BMI control are likely to slow disease progression in this population.

Systemic Symptoms in Huntington's Disease: A Comprehensive Review

BACKGROUND

Although Huntington's disease (HD) is usually thought of as a triad of motor, cognitive, and psychiatric symptoms, there is growing appreciation of HD as a systemic illness affecting the entire body.

OBJECTIVES

This review aims to draw attention to these systemic non-motor symptoms in HD.

METHODS

We identified relevant studies published in English by searching MEDLINE (from 1966 to September 2023), using the following subject headings: Huntington disease, autonomic, systemic, cardiovascular, respiratory, gastrointestinal, urinary, sexual and cutaneous, and additional specific symptoms.

RESULTS

Data from 123 articles were critically reviewed with focus on systemic features associated with HD, such as cardiovascular, respiratory, gastrointestinal, urinary, sexual and sweating.

CONCLUSION

This systematic review draws attention to a variety of systemic and autonomic co-morbidities in patients with HD. Not all of them correlate with the severity of the primary HD symptoms or CAG repeats. More research is needed to better understand the pathophysiology and treatment of systemic and autonomic dysfunction in HD.

Hypertension, antihypertensive drugs, and age at onset of Huntington's disease

BACKGROUND

Associations between blood pressure (BP) with age at onset of Huntington's disease (HD) have reported inconsistent findings. We used Mendelian randomization (MR) to assess effects of BP and lowering systolic BP (SBP) via the genes encoding targets of antihypertensive drugs on age at onset of HD.

METHODS

Genetic variants from genome-wide association studies(GWAS) of BP traits and BP-lowering variants in genes encoding antihypertensive drugs targets were extracted. Summary statistics for age at onset of HD were retrieved from the GWAS meta-analysis of HD residual age at onset from the GEM-HD Consortium included 9064 HD patients of European ancestry (4417 males and 4,647 females). MR estimates were calculated using the inverse variance weighted method, supplemented by MR-Egger, weighted median, and MR-PRESSO methods.

RESULTS

Genetically predicted SBP or diastolic BP increase was associated with a later age at onset of HD. However, after SBP/DBP was present as a covariate using multivariable MR method, no significant causal association was suggested. A 10-mm Hg reduction in SBP through variants in genes encoding targets of calcium channel blockers (CCB) was associated with an earlier age at onset of HD (β=-0.220 years, 95% CI =-0.337 to -0.102, P = 2.42 × 10^- 4). We did not find a causal association between angiotensin converting enzyme inhibitors and β-blockers with the earlier HD onset. No heterogeneity and horizontal pleiotropy were identified.

CONCLUSIONS

This MR analysis provided evidence that genetically determined SBP lowering through antihypertensive drugs might be associated with an earlier age at onset of HD. The results may have a potential impact on management of hypertension in the pre-motor-manifest HD population.

Posterior reversible encephalopathy syndrome due to arterial hypertension may mark the onset of the symptomatic phase in Huntington's disease

Autonomic dysregulation of cardiovascular functions marks early Huntingtons disease (HD). Blood-brain barrier (BBB) is dysfunctional in HD. A 37-year-old female carrying 41 CAG triplets in the huntingtin gene acutely presented with a multifaceted syndrome attributable to posterior reversible encephalopathy syndrome (PRES). Syndrome was associated with arterial hypertension (AHT). The syndrome fully recovered both by imaging and clinical signs after normalization of arterial pressure during hospitalization. Immediately after hospital discharge, the patient developed a complex psychiatric syndrome and choreic movements that represented conversion to the symptomatic phase of HD. A one-year later follow up clearly showed the patient had developed the symptomatic stage of HD by presenting both psychiatric symptoms and choreic movements. Onset of AHT may represent an early premonitory signal of HD becoming manifested. Induction of PRES might be associated with BBB impairment in HD.

Hypertension Is Associated With an Earlier Age of Onset of Huntington's Disease

BACKGROUND AND OBJECTIVE

Hypertension (HTN) is associated with worsening clinical outcomes in neurodegenerative diseases. The relationship between HTN and the age of diagnosis (ADx) of Huntington's disease (HD) is not clear, however. This study sought to determine if the presence of HTN in adult patients with premanifest HD was associated with an earlier ADx compared with normotensive patients with HD.

METHODS

Premanifest participants from Enroll-HD were included if they had a cytosine-adenine-guanine greater than or equal to 36, baseline diagnostic confidence level less than 4, baseline total functional capacity score greater than 11, and baseline motor score less than 21. There were 3020 premanifest participants with HD, and 293 reported a diagnosis of HTN. HTN was transformed into a time-dependent variable, and a Cox proportional hazard survival model determine if the presence of HTN affected the time to motor conversion. Baseline cytosine-adenine-guanine-age product score, cytosine-adenine-guanine repeat length, baseline age, sex, baseline body mass index, smoking history, and region were included as covariates.

RESULTS

Participants with HTN had an increased annualized hazard of motor conversion compared to normotensive participants with HD (hazard ratio, 1.29; 95% confidence interval, 1.02-1.64; P = 0.034).

CONCLUSIONS

A previous study reported a protective effect of HTN in HD, but did not account for the fact that the prevalence of HTN increases with age. By controlling for this confounder, we more accurately outline the association between the ADx of HD to demonstrate that a diagnosis of HTN may be associated with an earlier ADx of HD. These results represent an association, however, and further investigation is warranted. © 2020 International Parkinson and Movement Disorder Society.

Hypertension, Antihypertensive Use and the Delayed-Onset of Huntington's Disease

Background

Hypertension is a modifiable cardiovascular risk factor implicated in neurodegeneration and dementia risk. In Huntington's disease, a monogenic neurodegenerative disease, autonomic and vascular abnormalities have been reported. This study's objective was to examine the relationship between hypertension and disease severity and progression in Huntington's disease.

Methods

Using longitudinal data from the largest worldwide observational study of Huntington's disease (n = 14,534), we assessed the relationship between hypertension, disease severity, and rate of clinical progression in Huntington's disease mutation carriers. Propensity score matching was used to statistically match normotensive and hypertensive participants for age, sex, body mass index, ethnicity, and CAG length.

Results

Huntington's disease patients had a lower prevalence of hypertension compared with age‐matched gene‐negative controls. Huntington's disease patients with hypertension had worse cognitive function, a higher depression score, and more marked motor progression over time compared with Huntington's disease patients without hypertension. However, hypertensive patients taking antihypertensive medication had less motor, cognitive, and functional impairment than Huntington's disease patients with untreated hypertension and a later age of clinical onset compared with untreated hypertensive patients and normotensive individuals with Huntington's disease.

Conclusions

We report the novel finding that hypertension and antihypertensive medication use are associated with altered disease severity, progression, and clinical onset in patients with Huntington's disease. These findings have implications for the management of hypertension in Huntington's disease and suggest that prospective studies of the symptomatic or disease‐modifying potential of antihypertensives in neurodegenerative diseases are warranted. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.