Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days) type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS). Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young’s modulus), and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic and protective effect of zinc under chronic diabetic conditions. Furthermore, these results indicate that zinc supplementation could act as a complementary therapy in chronic T1DM.

We investigated the role of an evidence-based integrated group rehabilitation program on the treatment of patients with knee osteoarthritis (KOA). This was a two-group, randomized controlled, 8 wk trial with 41 patients with moderate to very severe KOA. Patients were assigned to an intervention group (IG) or control group (CG). After both groups had received a self-management education program, IG participants underwent a rehabilitation program, including educational aspects about KOA followed by exercises. CG participants received only general health orientation about KOA during this period. The outcome measures were the Lequesne algofunctional index; 36-Item Short Form Health Survey (SF-36); and chair-stand, sit-and-reach, timed up-and-go, and 6-minute walk tests. Analysis of covariance revealed significant postintervention improvements of IG participants compared with CG participants (p < 0.05) on Lequesne total score and pain and function subdomains; SF-36 physical function, role physical, bodily pain, general health, vitality, and role emotional subdomains; and performance assessed by chair-stand, timed up-and-go, and 6-minute walk tests. Focusing on the primary outcome (Lequesne total score), the mean +/- standard deviation after 8 wk was 5.50 +/- 2.98 for the IG and 7.87 +/- 3.48 for the CG (p = 0.009). The corresponding effect size (partial eta squared with 90% confidence interval) was 0.23 (0.04-0.42), indicating a large effect. The presented rehabilitation program reduced pain and improved quality of life and function in patients with KOA. ClinicalTrials.gov; Progressive Collective-exercise Program on the Knee Osteoarthritis; NCT01850862; https://clinicaltrials.gov/ct2/show/NCT01850862?term=NCT01850862&rank=1.