Under the watchful eye of Dr. Frederick Goetz, nearly one in seven residents of Wadena, Minn., came to a lab, drank a sugary mixture and had their blood and urine examined during a four-hour period.

The landmark two-year study of 720 of Wadena's 4,700 people in the mid-1980s reshaped how doctors gauge the long- and short-term risks of diabetes for healthy people and those with the disease.

It was among dozens of studies that Goetz spearheaded in his decades of diabetes research at the University of Minnesota.

Goetz died from complications of Parkinson's disease on Aug. 28. He was 90.

"He made enormous contributions to diabetes research and mentored all sorts of people here at the university," said Dr. John Bantle, professor of medicine and director of endocrinology and diabetes at the University of Minnesota. "He was the kindest and gentlest man imaginable."

Born in Fond du Lac, Wis., in 1922, Goetz graduated from Harvard College in 1943 and its medical school three years later. He met his wife of nearly 52 years, Mary Rose Riordan, while serving in Korea as a U.S. Army physician.

After a residency in internal medicine at Massachusetts General Hospital, he joined the University of Minnesota in 1955 as director of the diabetes clinic. For the next three decades, he wrote dozens of articles and conducted myriad studies that deepened the understanding of the role the pancreas and kidneys play in diabetes. That work helped save thousands of diabetics' lives through pancreas and kidney transplants.

In 1969, Goetz was named director of the university's new Clinical Research Center, which became a hub of diabetes research, publishing more than 100 articles and creating new standards for surgical treatment. Goetz's work aided in the understanding of Type 1 diabetes as a largely immunological disorder, while Type 2 is mainly acquired.

Goetz left the center in 1986 to track Wadena residents 160 miles northwest of the Twin Cities, showing how the risk for Type 2 diabetes increases with age as people's metabolic functions decline.

"The Wadena study showed us what happens to healthy people in terms of the slow, gradual decline of insulin production over time," Bantle said. "It had major implications for people with the diabetes, who experience the same thing to a greater extent."

In addition to his diabetes work, Goetz was the former president of the Basilica of St. Mary's parish council in Minneapolis. He was an avid sailor on Lake Superior and a founding member of the Apostles Islands Yacht Club in Bayfield, Wis. He also was an accomplished pianist.

"It always struck me how, when people learned who my father was, they'd always say what a kind man he is, or was," said Fred Goetz, a well-known Minneapolis defense attorney and one of the doctor's three surviving children. "We just don't have enough of those people around these days."

In addition to his son and wife, Goetz is survived by his daughter Dr. Laura Goetz of San Diego; son Thomas Goetz of San Francisco, and grandchildren Samuel, Micah, Rex and Buckminster.

Visitation will be held at the Basilica of St. Mary in Minneapolis on Sept. 28 at 10:30 a.m. followed by a funeral mass.

Curt Brown • 612-673-4767