Back Pain and Hormones
Ross Hauser, M.D., Marion Hauser, M.S.,R.D.

Dr. Jan Brynhildsen and colleagues from the Department of Obstetrics and Gynecology, Faculty of Health Sciences, University Hospital, Linkoping, Sweden, sent questionnaires to 1,324 women who were in menopause. This questionnaire included questions about current hormone replacement treatment, previous and current back problems, medical care for back problems, parity, exercise and smoking habits, and occupation.

The questionnaire was returned by 85 percent of the women. There was a significant positive association between current use of hormone replacement treatment and low back pain. Previous back problems during pregnancy was a strong risk factor for current back pain, whereas neither current smoking nor regular physical exercise was a risk factor (nor was exercise protective). Their conclusion was that women receiving hormone replacement treatment had a significantly higher prevalence of current back pain than non-users, which could not be explained by differences in occupation, smoking habits, or current physical activity. (Brynhildsen, J. Is hormone replacement therapy a risk factor for low back pain among postmenopausal women? Spine. 1998; 23:809-813.) They speculated that hormonal effects on joints and ligaments may be involved.

Others have also speculated that oral contraceptive pills are a risk factor for low back and pelvic pain among women.The theory proposes that estrogen steroid hormones affect joints and ligaments, leading to Pubic Symphysis weakening and low back pain. In our opinion, this is not theory, but fact. Estrogen negatively affects collagen growth with only one result emerging, and that result is not good. Many general practitioners, gynecologists, orthopedists, midwives, and physiotherapists (at least in Sweden) believe there is an association between the use of these estrogen pills and the development of back problems.

Approximately one-fourth of the active professionals in Sweden recommend that some women with back problems abandon their use of oral contraceptives. (Brynhildsen, J. Oral contraceptives and low back pain: Attitudes among physicians, midwives and physiotherapists. Acta. Obste. Gynecol. Scan. 1995; 74:714-717.)

Many believe the oral contraceptives increase the risk of back problems, just like what occurs during pregnancy. As many as 50 percent of all women experience back problems during pregnancy. Because back problems develop so early during pregnancy, they cannot be explained as related only to the increased mechanical stress from the weight gained in the front of the body; therefore, hormonal factors have been proposed as the cause. Sex hormones are thought to affect ligaments and increase flexibility in the pelvis. This increased flexibility, or laxity, then leads to the low back pain.

Back Pain, Hormones, Loose Ligament - The example of pregnancy.

During pregnancy, a woman's body secretes a hormone called relaxin, which causes ligaments to loosen allowing the baby to pass through the birth canal. Ligament laxity is normal during pregnancy. The baby's position in the pelvic region during pregnancy, the lax ligaments to allow delivery, and the mother carrying her baby on her hip after the baby is born all contribute to a resultant sacroiliac laxity and lower back pain so common in women.

Relaxin's effects include the production and remodeling of collagen, increasing the elasticity and relaxation of muscles, tendons, and ligaments. Relaxin given to estrogen-primed guinea pigs and mice produces an increase in ligament mass at the pubic symphysis. However, dry weight of collagen in this mass is actually decreased, indicating a decrease in collagen content and concentration. Collagen solubility does not increase with relaxin stimulation, indicating that the mechanism of action for relaxin on soft tissues must be proteolysis. Proteolysis is from the Greek word, proteios (protein) and lysis (loosening). Proteolysis is a process in which water is added to the peptide bonds of proteins, breaking down the protein molecule.

The point is that relaxin has a direct negative effect on the strength of collagen. Relaxin is secreted by all females, the highest levels being during the middle of the luteal phase (ovulation) of the menstrual cycle (days 20-23).

Because of the double whammy of estrogen and relaxin, women have increased ligamentous laxity and flexibility compared to their male counterparts.This excessive laxity is the reason that there is an increased incidence of patellar subluxations and ligament sprains seen in female athletes. (Glick, J. The female knee in athletics. Physician and Sports Medicine. 1973; 1:35-37.;Powers, J. Characteristic features of injuries in the knees of women. Clin. Orthop. Rel. Res. 979; 143:120-124.) This laxity is especially present during pregnancy when the risk of ankle sprains and ligamentous injuries is highest. (Lutter, J.M., Lee, V. Exercise in pregnancy. In Pearl AJ, (ed.), The Female Athlete in Human Kinetics. Champaign, IL: 1993; p. 81-86.) If this was not bad enough, articular cartilage has estrogen receptors located on it. Like ligamentous tissue, estrogen has a direct negative effect on cartilage growth and repair. (Rosner, I. Estradiol receptors in articular cartilage. Biochem. Biophys. Res. Commun. 1982; 106:1378-1382.)

The net effect of all of this is that the joints of females, even females who have no pain whatsoever, are not normal. They cannot possibly be normal because of all the negative effects of estrogen as the prime instigator and relaxin as a lessor instigator. The turnover time (or half-life) of ligaments and cartilage is about one to two years. This means that about half of the cartilage or ligaments is regenerated about every 300 to 700 days. This is a very, very slow rate. Fibroblastic cells, which make collagen, and chondrocytes that make cartilage tissue, are stable cells in the fact that they do not proliferate easily. They need to be stimulated to proliferate. Injury to tissue stimulates them to some degree, but exercise does not noticeably change this rate. The primary way to stimulate the fibroblasts and chondrocytes is by direct proliferative therapy (Prolotherapy). Prolotherapy injections are given right where the fibroblasts and chondrocytes are located-at the fibro-osseous junction. This is where ligaments attach to bone or directly on the outside of the cartilage. This causes a massive stimulation of fibroblastic and chondrocyte growth, with the net effect being ligament and cartilage growth. It is this treatment that offers the only hope to women to not only get rid of their chronic pain, but also cure their sports injuries.