Electrical field stimulation improves bone mineral density in ovariectomized rats

Abstract

Osteoporosis and its consequent fractures are a great social and medical problem mainly occurring in post-menopausal women. Effective forms of prevention and treatment of osteoporosis associated with lower costs and the least side effects are needed. Electrical fields are able to stimulate osteogenesis in fractures, but little is known about their action on osteoporotic tissue. The aim of the present study was to determine by bone densitometry the effects of electrical stimulation on ovariectomized female Wistar rats. Thirty rats (220 ± 10 g) were divided into three groups: sham surgery (SHAM), bilateral ovariectomy (OVX) and bilateral ovariectomy + electrical stimulation (OVX + ES). The OVX + ES group was submitted to a 20-min session of a low-intensity pulsed electrical field (1.5 MHz, 30 mW/cm 2 ) starting on the 7th day after surgery, five times a week (total = 55 sessions). Global, spine and limb bone mineral density were measured by dualenergy X-ray absorptiometry (DXA Hologic 4500A) before surgery and at the end of protocol (84 days after surgery). Electrical stimulation improved (P < 0.05) global (0.1522 ± 0.002), spine (0.1502 ± 0.003), and limb (0.1294 ± 0.003 g/cm 2 ) bone mineral density compared to OVX group (0.1447 ± 0.001, 0.1393 ± 0.002, and 0.1212 ± 0.001, respectively). The OVX + ES group also showed significantly higher global bone mineral content (9.547 ± 0.114 g) when compared to both SHAM (8.693 ± 0.165 g) and OVX (8.522 ± 0.207 g) groups (P < 0.05). We have demonstrated that electrical fields stimulate osteogenesis in ovariectomized female rats. Their efficacy in osteoporosis remains to be demonstrated.

The Female Athlete Triad

“…29 There has also been a recent movement toward the use of mechanical stimulation to treat bone loss because it mimics impact physical activity. Pulsed electromagnetic fields increase BMD in ovariectomized rats, 75 as well as in postmenopausal women. 120 Vibratory platforms can reduce and possibly prevent bone mass loss after only 20 minutes of quiet standing 104,114 and were correlated with BMD increases in 1 study of adolescent girls.…”

Long-term effects of ovariectomy on the properties of bone in goats

“…Thus, large animal models that accurately portray human osteoporotic changes are required for these studies. In previous studies, rats (5), large osteopenic animal models, such as nonhuman primates and sheep, have been used as models (6,7). However, the time required to establish an accurate osteoporosis model is unknown (8)(9)(10)(11)(12).…”

Nutritional Support and Physical Modalities for People with Osteoporosis: Current Opinion

“…Electrical stimulation of bone fusion is a technique that has been used for three decades. Three types of electrical stimulation technologies been approved for clinical use: direct current (DC); inductive coupling (IC) such as pulsed electromagnetic fields (PEMF) and combined magnetic fields (CMF); and capacitive coupling (CC) [74][75][76][77][78]. This section focuses on noninvasive IC and CC technologies because DC technology requires surgical implantation of the device.…”

“…PEMF and CMF consist of external current-carrying coils that produce a magnetic field, which induces a secondary electric field at the fusion site. The CC device consists of electrodes applied to conductive gel on the skin that produce an electric field at the fusion site [74][75][76][77][78].…”

“…For postmenopausal women with multiple fractures and chronic back pain, a larger proportion of an active group treated with CC stimulation were able to discontinue the use of NSAID to eliminate pain than that of a control group [75]. Several studies have found that electrical stimulation significantly promoted osteogenesis in osteoporotic or osteoporosis-prone women [76,77] and bilateral ovariectomy rats [78]. No negative side effects have been reported with IC and CC for bone growth over the past twenty years [75,79].…”