Insulin may up blood pressure in type 2 diabetics

Some people with type 2 diabetes need to take insulin, and this seems to heighten their risk of developing high blood pressure, according to a Taiwan study.

Type 2 diabetes is caused not by a lack of production of insulin in the pancreas, but by the body's resistance to its glucose regulating action. Nevertheless, some people with the condition may need to take extra insulin to overcome this resistance.

Using national health insurance records, Dr. Chin-Hsiao Tseng from the National Taiwan University Hospital in Taipei identified 87,850 adults with type 2 diabetes, including 5,927 insulin users.

The likelihood that they would have high blood pressure increased with the duration of insulin use, the team reports in the Archives of Internal Medicine.

Compared with those who didn't use insulin, the chances of developing high blood pressure were 14 percent higher in those who used insulin for less than 5 years. The risk was increased to 35 percent with 5 to 9 years of insulin use, and to 46 percent after 10 years or more.

The reason for this could be that people taking insulin "may be repetitively exposed to high concentrations of insulin," Tseng explains. "This excess of insulin may exert detrimental effects on the vascular system, leading to elevated blood pressure."

SOURCE: Archives of Internal Medicine, June 12, 2006.