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Top-selling insulin associated with increased cancer risk

A presentation at the San Antonio Breast Cancer Symposium revealed an increased risk of cancer in association with insulin glargine, the world's top-selling long-acting insulin analog which is marketed under the brand name Lantus®. In contrast, use of the antidiabetic drug metformin, available as a low-cost generic, was associated with an impressive reduction in cancer risk.

Hakan Olsson and colleagues from Sweden's Lund University analyzed data from 2,724 cancer patients up to ten years prior to diagnosis and 20,542 subjects with no history of the disease. They found that having diabetes within four years prior to being diagnosed with breast cancer was associated with a 37 percent greater risk of this type of cancer compared to nondiabetics. Obesity after the age of 60 was associated with a 55 percent greater breast cancer risk, and abnormally low blood lipids with a 25 percent greater risk in comparison with those who did not have these conditions.

When prescription drug use was examined, insulin glargine, a biosynthetic long-acting insulin analog, was associated with a whopping 2.9-times increased risk of cancer, whereas metformin was associated with a reduced risk of 8 percent. Although not all long-term studies of Lantus® suggest increased cancer risk, there remains concern that long-acting insulin analogs like Lantus® may have the potential to increase cancer risk.

Biosynthetic insulin analogs like Lantus® (insulin glargine) are not exactly the same as human insulin. Enhanced reactivity with the IGF-1 receptor are characteristics of these drugs. Stimulation of the IGF-1 (insulin-like growth factor-1) receptor has been shown in several studies to enhance tumor cell growth and proliferation. For example, insulin B10Asp, the first of the analogs to be developed, was based on a single amino acid substitution in comparison with human insulin. This was sufficient to produce a ten-fold increase in cell division (mitogenicity) compared with human insulin.

Modification of specific regions of the B-chain molecule associated with insulin (specifically, the B26–B30 regions of the B-chain) increase IGF-1 receptor binding, as does modification of the B10 residue and extension of the B-chain by addition of arginine residues. These modifications can produce a nearly 90-fold increase in binding to the IGF-1 receptor. Lantus® (insulin glargine) contains arginine residues at positions B31 and B32, together with a glycine substitution at A21.

While the use of insulin is a necessity for some type 2 diabetics, Life Extension® has long recommended that those who have diabetes or are at risk of the disease make every effort to control their blood glucose levels with a combination of consuming fewer and healthier calories, engaging in regular exercise, and supplementing with beneficial nutrients that may be insufficiently supplied by the diet. Soluble fiber, green bean coffee extract, magnesium, Irvingia gabonensis seed extract, L-carnitine, alpha-lipoic acid, and green tea are just a few examples of nutrients that can help support healthy glucose metabolism. Life Extension has long advocated an aggressive, integrative strategy to reduce ingested calorie intake and support healthy glucose metabolism. For more information, please contact a Life Extension Health Advisor at 1-800-226-2370.