Information for Medical Professionals

Four patients with uncontrolled hypertension were tracked for between 52 and 73 weeks, during which the actual IHG sessions per week averaged 2.57. Decreases in blood pressure were typically seen in the first 5-10 weeks of use and were maintained with continued use of IGH therapy. The average blood pressure at the beginning of the study was 154.25/95.75mmHg and at the end of the study it was down to 126.5/81.5.

Although participants were on at least one type of prescription medication, no adverse interactions or side effects were reported as a result of the IHG therapy. During the study participants were also either able to discontinue or stay off of antihypertension medications.

This study shows that blood pressure reductions as a result of IHG therapy can be maintained with continued IGH training. Dr. Geisbrug, the study's author, concluded, "Regular isometric handgrip training can be a useful tool in the treatment of hypertension in a family practice environment."

Normotensive participants completed 5 weeks of isometric arm training after which they saw a significant decrease in resting systolic blood pressure from 114.3+/-11.3 to 101.9+/-7.7 mmHg. Researchers were also able to determine that the decrease in blood pressure associated with isometric training was probably not because of changes in orthostatic tolerance.

Nine of the 20 participants who began this trial had established coronary artery disease. All participants were medicated for hypertension and were taking either one or a combination of Ace Inhibitor, Beta Blocker, Calcium Channel Blocker and/or Diuretic for an average of 7.7 +/- 7.3 years.

The researchers concluded, "... IHG training, using a simple hand-held, non-time consuming device that requires minimal effort to perform, improves local, dysfunctional endothelium in persons medicated for hypertension to values within the normal range."

After 8 weeks of IHG training medicated hypertensive patients, 6 with coronary artery disease, saw significant declines in resting blood pressure. At baseline, the average systolic blood pressure in the bilateral training group was 133.9/73.2mmHg and by the end of the study it had dropped to 118.5/67.2mmHg. The unilateral group also saw a decrease, from 141.6/79.6mmHg to 132.4/76mmHg.

The study concluded, "IHG training could be an important addition to the pharmacologic management of hypertension, and may potentially reduce stroke, coronary artery disease and mortality." They also found that IHG training improves endothelial-dependant vasodilatation in the trained limbs and suggest that other mechanisms are most likely involved in the observed blood pressure reductions as well.

Although this paper focused on mechanisms, it did also report a statistically significant drop in the systolic blood pressure of medicated hypertensives participants who performed IHG therapy from 137+/-5.3 to 121.7+/-4.8mmHg.

The researchers concluded, "IHG training improves systolic BP and endothelial function in persons medicated for hypertension."

This is a published review of known literature regarding reducing blood pressure through IHG therapy. The author concluded, "The positive results of IHG training support its use as a non-pharmacologic treatment for hypertension."

Data from three previous studies which included 43 medicated hypertensives were analyzed and found to show significant decrease in average blood pressure from 139/79.84mmHg to 135.11/77.03 over the course of 8 weeks of IHG training.

The study's authors reported, "Hierarchical linear modeling analysis revealed a linear pattern of blood pressure decline over time with estimated reductions of 5.7 and 3mmHg reductions in systolic and diastolic pressure, respectively. Participants with higher initial systolic pressure showed greater rates of blood pressure decline ( r= -0.67 ), inferring that individuals with higher blood pressure stand to achieve greater benefits from this method of training."

Subjects in this study completed IHG exercise and a time-matched control condition in a randomized, crossover design. There was a significant reduction in systolic blood pressure of 3mmHg 5 minutes after a single bout of bilateral IHG, even though participants were classified as normotensive.

According to the study, "These results suggest improvements in acute cardiac autonomic modulation following a single bout of IHG." The authors speculate that "these alterations may be responsible for the increases in parasympathetic activity and reductions in resting ABP [arterial blood pressure] observed with chronic use of IHG training."

In this study, unmedicated hypertensive adults who performed IHG therapy for six weeks saw a decrease in systolic blood pressure of 13mmHg on average, taking them from an average systolic blood pressure of 146 to 133mmHg. Markers of oxidative stress were also analyzed and led researchers to report that enhanced antioxidant protection as a result of IHG training was most likely an underlying mechanism.

In summary, the researchers, "...conclude that the IET protocol followed with the CardioGrip handgrip dynamometer reduces SBP [systolic blood pressure] in hypertensives and one of the underlying mechanisms is a favorable change in oxidative stress."

Normotensive participants in this study documented statistically significant decreases in diastolic blood pressure from an average of 67+/-1 to 62+/-1mmHg as well as a reduction in mean arterial pressure from 86+/-1 to 82+/-1mmHg.

The study also reported that the mechanism for the blood pressure reductions in this normotensive population appeared not to be because of a change in muscle sympathetic nerve activity (MSNA), but rather possibly due to peripheral vascular adaptations. The researchers further clarified that while, "reductions in sympathetic outflow to skeletal muscle do not appear to be a prerequisite to lower arterial pressure in humans... it cannot be excluded that sympathetic outflow to vascular beds (e.g. visceral regions) may have been reduced and may have contributed to the reduction in arterial pressure at rest." In addition, the report notes that in hypertensives it may be possible that the changes in MSNA could contribute to blood pressure reductions.

This study involved hypertensive individuals, 75% of which were on blood pressure medications, who performed IHG therapy for 10 weeks. By the end of that time, their average systolic blood pressure significantly decreased from 156 +/- 9.4 to 137 +/- 7.8 mmHg and was also significantly different from the control group.

Through analysis of heart rate variability, the study was also able to determine that there was a decrease in the sympathetic modulation of cardiac function and an increase in the parasympathetic. The authors finished with stating that they "showed that [IHG] training attenuated the resting arterial pressure and was associated with a corresponding change in sympathovagal balance. We conclude that isometric handgrip training at modest intensity could be a useful adjunct to the pharmacological treatment of hypertension."

Participants in this study, although they were already being medicated for hypertension, were reported to have a significant decrease in their systolic blood pressure from 140.2 to 132.3mmHg after 8 weeks of IHG training. In addition, researchers were able to determine that carotid arterial distensibility improved after the IHG training.

These studies were some of the introductory investigations into IHG protocol. Both study 1 and 2 reported significant reductions in systolic and diastolic blood pressures following several weeks of IHG training (average decrease of 12.5/14.9 and 9.5/8.9 respectively). In study 2 they also found that after ceasing the IHG training, participants blood pressures gradually returned to their pre-IHG training levels over a 5 week period.

This study also comments on the safety of the IHG therapy, explaining that the interrupted isometric contraction involved in this therapy acutely raises blood pressure only modestly, avoiding potentially dangerous rises associated with continuously held fatiguing isometric contractions.