HTN: Vitamins (2015)


Mateus-Hamdan L, Beauchet O, Bouvard B, Legrand E, Fantino B, Annweiler C. High parathyroid hormone, but not low vitamin D concentrations, expose elderly inpatients to hypertension. Geriatr Gerontol. 2013; 13: 783-791.

PubMed ID: 22994947
Study Design:
Cross-Sectional Study
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
To examine the association of serum intact PTH and 25 OHD concentrations with BP levels amongst older in-patients, while accounting for each other.
Inclusion Criteria:
  • Elderly patient admitted to the geriatric acute care unit of Angers University Hospital, Angers, France
  • Provided written informed consent.
Exclusion Criteria:
Suspected primary hyperparathyroidism (i.e., serum PTH concentrations greater than 65pg per ml not linked to hypovitaminosis D, defined by serum 25OHD concentration less than 75nmol per L without using calcium supplements and vitamin D).
Description of Study Protocol:


Between January 2009 and October 2009, a standardized comprehensive geriatric assessment was obtained from all patients admitted to the geriatric acute care unit of Angers University Hospital, Angers France 


Cross-sectional studies.

Statistical Analysis

  • Participants characteristics were summarized using means and standard deviations or frequencies and percentages as appropriate
  • The normality of data distribution was checked using skewness-kurtosis
  • Comparisons between participants separated into two groups based on supine blood pressure levels (either hypertensive defined by supine SBP higher than 140mm Hg and supine DBP higher than 90mm Hg or nomotensive) were carried out using the X2 test or the independent samples T-test as appropriate
  • Second, adjusted linear regressions were used to examine the association of SBP with serum 25OHD and PTH concentrations 
  • Univariate and multiple logistic regressions were used to examine the association of hypertension dependent with serum 25OHD and PTH concentrations
  • P values less than 0.05 were considered statistically significant.


Data Collection Summary:

Timing of Measurements

  • Fasting early morning; venous blood was collected from resting participants for the measurement of serum intact PTH and 25OHD concentrations as well as other biological covariates
  • Serum 25OHD concentrations were measured using radioimmunoassay.

Dependent Variables

  • Hypertension
  • Blood pressure was measured at rest in a quiet environment with trained nurses
    • Each measurement was recorded using a standard protocol defined by the American Heart Association using a sphygamometer placed on the brachial artery with the arm at heart level
    • Baseline values were obtained after at least 15 minutes of rest in the supine position
    • Hypertension was defined by a supine systolic blood pressure (SBP) higher than 140mm Hg or a supine diastolic blood pressure (DBP) higher than 90mm Hg.
Independent Variables
  • Serum Vitamin D (25OHD)
  • Serum parathyroid hormone.
Control Variables
  • Gender
  • Antihypertensive drugs use
  • Calcium supplements/vitamin D
  • Corticosteroid drugs use
  • Number of chronic diseases
  • Number of drugs taken per day
  • Serum PTH
  • Serum 25OHD
  • Serum TSH
  • Serum albumin
  • Creatinine clearance.
Description of Actual Data Sample:
  • Initial N: 289
  • Attrition (final N): 284 (65.8% female)
  • Age: Mean age, 85.87±5.9 years
  • Ethnicity: NA
  • Other relevant demographics: 37.3% with hypertension
  • Anthropometrics: NA
  • Location: Angers, France.
Summary of Results:

Key Findings

  • Hypertensive participants (N=106) had higher intact PTH concentrations than normotensive patients (P=0.044)
  • There was a positive linear association of BP with intact PTH concentrations (adjusted B=0.08, P=0.015 for SBP; adjusted B=0.05, P=0.044 for DBP), but not with vitamin D
  • Serum intact PTH concentration, unlike 25OHD, was associated with hypertension (adjusted OR 1.01, P=0.038).
Author Conclusion:
The present study reports a significant positive association between increased serum PTH concentration and hypertension, which was manifested by the increase in both systolic and diastolic blood pressures. This result led us to suggest that PTH status could explain previous mixed results regarding the relationship between 25OHD and BP levels. If increased PTH concentration could affect BP, interventions aimed to normalize this hormone represent an interestingly accessible strategy for hypertension management.
Funding Source:
University/Hospital: Angers University Hospital
Reviewer Comments:
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? Yes
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes