Steve Jobs may have symptoms that resemble Type 1 diabetes, a noted endocrinologist said on Monday, and he could be treated with insulin.

Earlier on Monday, Jobs blamed a "hormone imbalance" for the weight loss that had sparked speculation about his health since last June, when he appeared at Apple's annual developer's conference looking gaunt.

Much of the talk about his appearance, and concern by investors about his condition, centered around the possibility that he again had cancer.

In August 2004, Jobs, who is 53, announced he had had surgery to remove a cancerous neuroendocrine tumor in his pancreas.

According to Dr. Run Yu, the director of the Carcinoid and Neuroendocrine Tumor Center at Cedars-Sinai Medical Center in Los Angeles, there are two likely explanations for Jobs' weight loss.

"A lot of this is speculative," Yu said to preface his reasoning, "since I don't know Mr. Jobs' condition specifically. But in terms of weight loss, and if the tumour was completely removed, it would be likely that he would have secondary Type 1-like diabetes. That's very common with patients who have had a large chunk of their pancreas removed," said Yu. "I see that very commonly."

When patients have surgery similar to Jobs', surgeons may have to remove many of the "beta cells," the type of cell in the pancreas that produces and releases insulin, along with the portion of the pancreas.

"When you remove a large chunk of the pancreas, you often have insufficient insulin," said Yu. "I would think that [Jobs] has Type 1-like diabetes."

Technically, Yu explained, Jobs would not have Type 1 diabetes, but the symptoms and treatment are identical. If so, insulin would be the recommended treatment.

Another explanation that would fit Jobs' history and the statements he made Monday would be a digestive enzyme deficiency, which would also have been caused by the removal of the cancerous tumour four years ago.

"A likely clinical diagnosis would be poor absorption of nutrients," said Yu. "The enzymes produced in the pancreas help us digest foods."

If Jobs' body is not generating those enzymes, he would not be able to efficiently draw nourishment from what he ate, Yu said.

The treatment for that, he said, would be an enzyme supplement, likely created from animal pancreases, that can be sprinkled on food. "You put it on your food, and eat the food along with the enzyme," said Yu. "It's very straightforward."

Jobs himself used the phrase "simple and straightforward" to describe his treatment, saying that his doctors had discovered he has a "a hormone imbalance that has been 'robbing' me of the proteins my body needs to be healthy."

Yu said it's likely that Jobs may have been confused about the hormone imbalance. "I can only surmise, but I think he's making a mistake," said Yu. "An enzyme imbalance, not a hormone imbalance, would rob his body of the proteins it needs."

Jobs' health has been an issue for some investors, and the focus of intense speculation by others, for more than six months.

In July, about a month after his appearance at the Worldwide Developers Conference, Jobs talked off the record with a reporter at The New York Times , who later said only that the Apple CEO's problems "weren't life-threatening, and he doesn't have a recurrence of cancer."

In the months since then, several incidents, including an obituary mistakenly published by the Bloomberg financial news service and a bogus report that Jobs suffered a major heart attack in October, sent Apple's stock tumbling.

Just last week, a report labelled "rumour" by the Gizmodo gadget blog saying that Jobs' "health is rapidly declining" knocked Apple share prices down for part of a day.

Contrary to those rumours, Yu said Monday that the prognosis for someone like Jobs is "very good."

Even so, Yu noted that without all the information, he is essentially guessing. "I'm not ruling out other things," he said. "But those [the Type 1-like diabetes and enzyme deficiency] would be ... the most common scenarios."

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