Osteoporosis is undoubtedly one of the most common diseases affecting older individuals with debilitating consequences. Osteopenia, defined as T-score between -1 and -2.5, has also been associated with increased risk of osteoporotic fractures and the associated morbidity and mortality. Prompt diagnosis, prevention and treatment of both osteopenia and osteoporosis are essential in order to minimize future fracture risk. The mainstay of treatment of osteopenia and osteoporosis includes dietary changes, regular weight-bearing exercises, calcium and vitamin D supplementation and pharmacologic treatment mainly with antiresorptive or anabolic agents. Collagen peptides (CPs), also called collagen hydrolysates produced by hydrolysis of collagen, have also been shown to have high oral bioavailability and could have a place as a treatment option.

Type I collagen comprises approximately 95% of the entire collagen content of bone. Bone matrix, unlike other connective tissues, possesses the unique ability to become calcified. Spindle or plate-shaped crystals of hydroxyapatite are found between and around collagen fibers, oriented in the same direction as collagen fibers are. Nowadays, it is well-documented that type I collagen molecules are involved in the mechanical properties of bone. Collagen peptide compounds seem to exert their beneficial effect on bone by affecting bone remodeling and mineralization of the bone matrix, promoting the proliferation and differentiation of pre-osteoblasts while reducing the maturation of osteoclasts. Several preclinical studies performed in mice and rats support this notion and also suggested that orally administrated CPs increased bone mineral density (BMD), as well as the compositional and the biodynamic characteristics of vertebrae. Human studies in postmenopausal women have also yielded positive results with increased BMD and blood biomarkers after 6 months and 1 year of oral administration.

The aim of the present randomized prospective study was to examine and compare the efficacy, as represented by the changes in bone biomarkers procollagen type I N-terminal propeptide (P1NP) and C-terminal telopeptide of collagen I (CTX), and bone mineral density and the tolerability of supplementation of calcium, vitamin D with and without bioactive CPs for a year in postmenopausal women with osteopenia.

Inclusion Criteria:

• Postmenopausal women
• T-score in the osteopenic range (-1.0 > T-score > -2.5) at either the lumbar spine (LS) or femur as measured by dual energy X-ray absorptiometry (DXA)

Exclusion Criteria:

• T-score in the osteoporotic range (T-score < -2.5) at any site
• Patients receiving supplements of calcium and/or vitamin D at that time or during the last year
• Patients receiving medications known to positively or negatively affect bone turnover or BMD at that time or during the last 3 years (e.g. antiresorptive agents, oestrogens, systemic corticosteroids), or
• Secondary cause of osteoporosis (e.g. alcohol abuse, thyrotoxicosis etc)
• Patients who did not attend to their follow-up appointment and consequently had only the baseline measurements

Postmenopausal osteopenia