The team found that the extract reduces blood sugar in type II diabetes patients, allows people to lower their antihypertensive medication and improves cardiovascular disease (CVD) risk factors.
The study, conducted at the University of Arizona, Tucson, indicates Pycnogenol may serve as a potent adjunct to prescription medications for diabetics.
"Most people with type II diabetes have cholesterol problems and half of those people experience hypertension. It has been documented that Pycnogenol mediates a number of beneficial effects on the cardiovascular system for diabetics and healthy individuals," said Dr. Ronald Watson, a lead researcher of the study.
"Previous studies have shown Pycnogenol supplementation to be associated with reducing platelet aggregation, lowering LDL and increasing HDL cholesterol and modifying hypertension, among others.
"But what really makes the study results compelling is Pycnogenol simultaneously lowered blood glucose, LDL cholesterol and blood pressure in patients. Furthermore, this is the first study suggesting that Pycnogenol might also be beneficial in protecting kidney function in diabetics," he added.
The 12-week, randomized, double-blind, placebo-controlled trial consisted of 48 men and women, 40 to 75 years of age, with noninsulin-dependent type II diabetes, taking anti-diabetic medication with metformin, sulfonylurea and glitazones.
Furthermore, they took antihypertensive medications with ACE inhibitors such as Lisinopril. Despite their medication their fasting blood sugar was above healthy values (142 mg/dL) and their average systolic blood pressure was 139 mmHg subjects were randomly assigned to receive either Pycnogenol (25 mg, 5 times daily) or matched placebo. Participants were instructed to continue taking their prescription medications.
Blood pressure and heart rate were recorded at baseline and at biweekly follow-up visits physicians tried to lower the patient's individual anti-hypertensive medication with aim to keep it below 130 mmHg. At monthly follow-up visits, all unused prescription medications were collected and counted.
Change from baseline at weeks four, eight and 12 were calculated after eight hours of fasting for assessing plasma glucose, LDL cholesterol and endothelin-1. Urinary protein concentration was measured from spot urine samples on a monthly basis.
In the Pycnogenol treated groups, results revealed Pycnogenol achieved blood pressure control in 58.3 percent of patients at the end of the 12 weeks with 50 percent reduction in prescription medications. Plasma endothelin-1, a very potent hormone-like arterial constrictor, which is, typically elevated in diabetes patients, decreased by 17.8 percent.
The constriction of arteries is believed to be the cause of hypertension and the decreased endothelin-1 with Pycnogenol is suggested to be the cause for the healthier blood pressure. The mean average blood glucose decreased from high 142.3 mg/dL to a healthy value 118.6, a decrease by 16.7 percent after 12 weeks. Low-density lipoprotein cholesterol improved significantly, declining by 11.9 percent.
"It is amazing to see that adding Pycnogenol to the regimen of prescription medication brought blood glucose to healthy levels, allowed half the patients to reach healthy blood pressure and enabled 58% to even lower their anti-hypertensive medication," said Watson.
"An absolutely new finding is that Pycnogenol appears to improve kidney function in diabetic people, this deserves more attention in future investigations. Pycnogenol should be standard adjunct to pharmaceutical treatment of diabetic patients to help control an array of cardiovascular problems."
The study appears in the May 2008 (volume 8, issue 25) edition of the journal of Nutrition Research.