Middle-Age Women and DCS

Every diver must be concerned about decompression sickness, especially as we age. The 50-year old body is not a 30-year-old body; and a 70-year-old body is not a 50-year-old body. But women divers, it seems, have a special set of issues associated with menopause. As a longtime diver, divemaster and middleaged woman, I've met more than a half dozen 50-plus women who've been diagnosed with DCS. I've seen numerous cases in Cozumel, where I dive every year. All these women claim to have been bent while staying within the recreational dive limits. We know fitness and aging are important factors in the DCS equation. But the question that interested me is whether aging women face additional risks as their bodies change with menopause.

Undercurrent ran a story in 2006 about research done on women divers and their menstrual cycles ( www.undercurrent.org/UCnow/dive_magazine/2006/MenstrualCycles200608.html ). But what do we know today about menopause and its possible effects on DCS risks? "There are no answers," says Neal Pollock, research director at Divers Alert Network. "We have a very tiny research budget and staff, and there are a lot of questions." Of course, there are researchers elsewhere with an interest in the topic, though it doesn't seem to be getting much attention.

However, physiological differences between men and women may have an impact on nitrogen loading. First, men (even those who aren't gym rats) generally have more muscle mass, and thus a better ratio of muscle to fat. "If you compare two people with equal amounts of fat, but one has less muscle and one has more, the one with less muscle is probably at greater DCS risk," says Pollack. That's because fat unloads nitrogen more slowly than muscle does.

Also a diver with less muscle mass will work harder in currents or on the surface, thus stressing her body more. If that diver is yo-yo diving too, as is popular in Cozumel, that could be a formula for trouble. Another difference: Women tend to get colder than men do. "If you have a lot of uptake of gas, say on a deeper or longer dive, you have tissues loaded with gas as you get cold, and you have impaired unloading," says Pollack.

In addition, says Dr. Margery Gass, executive director of the The North American Menopause Society, "Women do start to lose a little bit of bone at menopause...then [the rate of] loss goes to same loss that men experience, as it relates to aging." Aging women need to play attention to bone health, and bone and muscle strength. Gass says that DCS may occasionally lead to osteonecrosis, which means that part of a bone does not get blood and dies. It is a little discussed risk of DCS.

Okay, so are women, especially older women, at more risk for DCS, even if we don't yet have a study to prove it? Yes, and no. "I believe that women are at a slightly greater risk for DCS physiologically," says Pollock. "However, women are behaviorally much safer than men. They don't have the same stupid gene men have." And thus, they're less likely to take foolish risks in diving and other activities.

Watch Your Weight, Heave Some, Too

In the age of super-sized fast food, divers need to make smart choices. Obesity increases all types of health risks for women and men, not just DCS. Staying strong and maintaining muscle mass is vitally important for postmenopausal women divers. And older male divers should incorporate strength training into their fitness regimes too.

Los Angeles-based fitness guru Kathy Kaehler, author of Fit and Sexy for Life, is a huge proponent of strength training for women. She says that with commitment, middle-age women can dramatically improve their body fat ratios. A woman with poor fitness might have a body-fat percentage in the high 30s to low 40s, but with proper strength and fitness training, she could lower that percentage to the mid to low 20s in a year. The reality is that as we age, we have to work very hard to put on and maintain muscle. "I've gone through menopause, and the first thing that left me was my muscle - that was my wake-up call," says Kaehler.

As for all aging divers, Pollack has this advice: Dive more conservatively as you age, and be honest in your appraisal of your abilities. Also, "stay physically fit and make sure you're medically fit."

In addition, give yourself a safety margin by always doing a minimum of a five-minute safety stop. More is better." Also make all your dives multilevel, says Pollack. "Once you leave a depth, don't return to it." No more yo-yoing.

Kathleen Doler is a divemaster, freelance writer and lifetime fitness fanatic who lives in Truckee, CA.

(Note from Ben: Research has shown that patent foramen ovale, a heart condition found in a significant percentage of the population, increases susceptibility to the bends in both sexes, regardless of whether they dive within the limits of decompression tables.)