PMID 30405426

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Prevalence of Non-responders for Blood Pressure and Cardiometabolic Risk Factors Among Prehypertensive Women After Long-Term High-Intensity Interval Training

Álvarez C, Ramírez-Campillo R, Cristi-Montero C, Ramírez-Vélez R, Izquierdo M

Question

Does 16 weeks of HIIT change blood pressure and cardiometabolic risk factors, and what is the prevalence of non-responders, among prehypertensive compared with normotensive sedentary overweight or obese women?

Summary

Sedentary overweight or obese women completed 16 weeks of supervised cycling HIIT. Women classified as prehypertensive had meaningful average reductions in systolic and diastolic blood pressure, while normotensive women did not show the same blood pressure benefit. Both groups improved several body composition, metabolic, and walking-performance measures. Baseline systolic blood pressure was the simplest predictor of systolic blood pressure reduction, but the paper has no true non-exercise control group and reports some internally inconsistent non-responder percentages for blood pressure.

Methodology

  • Sedentary overweight or obese adult women from Los Lagos, Chile, analyzed as prehypertensive (n=44) or normotensive (n=40) cohorts.
  • 84 participants.
  • Cycle ergometer.
  • Work intervals: 1 minute.
  • Recovery: 2 minutes inactive recovery.
  • Intensity: 8-10 on modified Borg 1-10 scale; approximately 70-100% age-based maximum heart rate.
  • 21-30 minutes.
  • 3 sessions/week.
  • 16 weeks.
  • Longitudinal exercise intervention with non-randomized comparison by baseline blood pressure status; both groups received HIIT.
  • Systolic blood pressure, Diastolic blood pressure, Body composition, and Fasting glucose and lipids were tracked.

Outcomes

Systolic blood pressure

PreHTN SBP decreased from 128 +/- 6 to 120 +/- 6 mmHg (delta -8 +/- 7); NTG changed from 108 +/- 5 to 111 +/- 8 mmHg (delta +3 +/- 9.8).

PreHTN within-group P < 0.0001; between-group delta reported P < 0.0001 in table and P < 0.003 in text.

Improved

Diastolic blood pressure

PreHTN DBP decreased from 85 +/- 8 to 80 +/- 10 mmHg (delta -5.8 +/- 11.7); NTG changed from 75 +/- 10 to 73 +/- 10 mmHg (delta -2.0 +/- 4.9).

PreHTN within-group P < 0.0001; between-group delta P < 0.001 in table and P = 0.007 in text.

Improved

Body composition

Both groups reduced body mass, BMI, skinfolds, and fat mass; waist circumference and abdominal skinfold changes differed significantly between groups.

Examples: PreHTN body mass -3.3 kg, NTG -2.0 kg; fat mass -5.8% and -3.8%; waist circumference delta between groups P = 0.037.

Improved

Metabolic markers

Fasting glucose and triglycerides decreased in both groups; HDL-C increased in PreHTN; total cholesterol and LDL-C decreased significantly in NTG but not PreHTN.

Fasting glucose delta comparison P < 0.01; LDL-C delta comparison P < 0.01; triglyceride delta comparison P = 0.045.

Mixed

Non-responder prevalence

The paper reports different non-responder prevalence by blood pressure status, but blood-pressure NR percentages differ across sections.

Abstract reports SBP NR 11.4% vs 68.8%; discussion reports SBP 11.4% vs 68.8% and DBP 31.8% vs 35.0%; results paragraph reports SBP 54.5% vs 92.5% and DBP 54.5% vs 85.0%, each P < 0.0001.

Mixed

Prediction of systolic blood pressure response

Baseline SBP alone was the simplest model and explained 51.2% of variance in SBP change.

Model 1 R=0.715, R2=0.512, P < 0.0001; Model 3 R2=0.538.

Improved

Insights

  • A supervised 1-minute hard / 2-minute rest cycling HIIT protocol can be a time-efficient blood-pressure intervention candidate for sedentary overweight or obese prehypertensive women.
  • Blood pressure expectations should be conditioned on baseline blood pressure; normotensive participants may not lower SBP.
  • Consumer programming should preserve screening, progression, and monitoring cautions because the studied sessions were supervised and individual blood pressure increases occurred.

Limitations

  • No true no-exercise control group.
  • Non-randomized grouping by baseline blood pressure status.
  • Women-only sedentary overweight/obese sample.
  • BIA was used for body composition rather than a gold-standard method.
  • Diet was not controlled.
  • Some baseline variables were nearly significantly different.
  • Blood-pressure non-responder percentages are internally inconsistent across sections.

Safety

  • No adverse events or injuries were reported in the paper.
  • Participants with cardiovascular contraindications, stroke history, asthma/COPD, musculoskeletal disorders, or recent smoking were excluded.
  • Individual increases in systolic blood pressure were observed and discussed as adverse-response-relevant variability.