NA: Incidence of Hypertension (2009)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To ascertain the presence of hypertension in in children of families with essential hypertension (EH) and to identify any markers in childhood that are predictive for the development of EH in adults.

Inclusion Criteria:
  • Children aged two to 18 years with a parent or grandparent with EH
  • Children aged two to 18 years from non-hypertensive families.
Exclusion Criteria:

N/A

Description of Study Protocol:

Recruitment

Not mentioned but said study was carried out at a public hospital over a one and a half-year period 

Design

  • 90 children (two to 18 years of age) from families with EH age matched with 25 children from non-hypertensive families
  • Various anthropometric and clinical measurements were conducted on four separate occasions one month apart.  

Blinding used

N/A 

Intervention

N/A 

Statistical Analysis

 Paired students T-test 

 

Data Collection Summary:

Timing of Measurements

Four sets of measurements one month apart

 Dependent Variables

  • BP after a half hour resting period with two readings a half hour apart with fourth phase of Korotkoff sound taken as DBP 
  • Fasting blood sample measured for serum cholesterol, triglycerides, HDL were estimated by enzyme assay
  • Serum Ca measured by cresolpthalene complexon method 
  • 24-hour urinary Na and K measured using a flame photometer.

Independent Variables

  • Weight measured by floor weighing scale
  • Height recorded against a standard vertical sliding scale
  • Triceps skin-fold thickness measured using Ponderal skin-fold measuring instrument
  • BMI calculated by standard formula
  • Dietary evaluation included calorie, protein, salt and fat intake.

 Control Variables

Age

 

Description of Actual Data Sample:

Initial N

135 children (90 from families with hypertension, 25 from non-hypertensive families)   

Attrition (final N)

Same as initial

Age

Two to 18 years

Ethnicity

Indian (from the country of India)

Other relevant demographics

N/A

Anthropometrics

  • NS difference in height between groups (hypertensive 133.48±14.92cm, control 127.72±24.65cm)
  • NS difference in BMI between groups (hypertensive 16.64±2.54, control 15.80±2.54)
  • Study group had greater skin-fold thickness than controls (hypertensive 9.13±3.35cm, control 7.12±1.69cm; P<0.001).

Location

India 

 

Summary of Results:

 Dietary Factors

  • NS difference in intake of calories per day between groups (hypertensive 1,700±428.5, control 1,608.8±372.36)
  • NS difference in intake of proteins per day (g) between groups (hypertensive 34.08±11.43, control 34.48±11.08cm)
  • Hypertensive group had higher intake of salt per day (g) (hypertensive 11.50±2.71, control 7.08±1.35; P<0.001)
  • Hypertensive group had higher intake of fat per day (g) (hypertensive 17.87±3.37, control 15.92±2.89; P<0.05).

Blood Measurements

  • Hypertensive group had higher serum cholesterol (mg/dL) (hypertensive 198.98±43.77 control 182.8±35.01; P<0.05)
  • Hypertensive group had higher serum triglycerides (mg/dL) (hypertensive 171.68±87.61, control 138.48±31.0; P<0.05)
  • NS difference in serum HDL between groups (hypertensive 53.12±6.91, control 48.88±6.59)
  • NS difference in serum Ca between groups (hypertensive 9.06±1.02, control 8.93±0.85).

Urinary Measurements

  • NS difference in urinary K (mEq/L) between groups (hypertensive 24.71±15.65, control 20.92±10.05)
  • Hypertensive group had higher urinary Na (mEq/dL) (hypertensive 99.86±23.42, control 86.72±26.98; P<0.05).
Author Conclusion:

Children belonging to hypertensive families should be targeted for primary prevention in a vigorous manner (BP and weight monitoring) along with dietary and lifestyle modifications. Diet should include supplement of high fiber diet to reduce serum cholesterol and increase serum HDL and restriction of salt and polyunsaturated fat. Encouragement of physical activity, discouraging smoking and alcohol abuse, beginning from childhood and continuing through adolescence to decrease the risk of development of EH and its associated complications especially in this target population.

Indian studies on long term follow up of children with EH is necessary along with the evaluation of factors whose role is now being implicated in the pathogenesis such as serum Ca, low birth weight and catecholamines etc.

 

 

Funding Source:
Other: Article states none
Reviewer Comments:

Study was for too short a period, no mention of change in variables from baseline to end of study, no breakout of results by age or gender, no mention of gender of subjects, low number of controls and no dietary intervention.

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) N/A
  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? N/A
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) N/A
 
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? No
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? ???
2. Was the selection of study subjects/patients free from bias? ???
  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? No
  2.2. Were criteria applied equally to all study groups? ???
  2.3. Were health, demographics, and other characteristics of subjects described? No
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? No
  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? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? N/A
  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.) ???
  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? No
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? ???
  4.4. Were reasons for withdrawals similar across groups? N/A
  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? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  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.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  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? N/A
  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? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  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? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? ???
  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? No
  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? No
  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? No
  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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  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? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? N/A
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? No
10. Is bias due to study's funding or sponsorship unlikely? N/A
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes