Maria Jesus Peña

Publications of Maria Jesus Peña

• [Bone mass loss after sleeve gastrectomy: a prospective comparative study with gastric bypass].

  Authors: Xavier Nogués, Albert Goday, Maria Jesus Peña, David Benaiges, Marta de Ramón, Xenia Crous, Manuel Vial, Manuel Pera, Luis Grande, Adolfo Díez-Pérez, Jose Manuel Ramón

  Cirugía española. 08/2010; 88(2):103-9.

  Bariatric surgery is the most effective option for the treatment of patients with a high risk of complications due to their obesity. However, it brings about a series of changes in calcium andBariatric surgery is the most effective option for the treatment of patients with a high risk of complications due to their obesity. However, it brings about a series of changes in calcium and vitamin D metabolism and an increase in resorption which lead to a loss of bone mass. The objective of this study is to compare sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) as regards loss of bone mass using bone densitometry and bone remodelling markers. Fifteen women with morbid obesity were included, 8 by SG and 7 by RYGB, with a mean age of 47.8+/-9 and mean body mass index 43.3+/-3.4. Bone mass measurements were made on the lumbar spine, femur and distal radius, and the bone remodelling markers N-telopeptide (NTx) and bone alkaline phosphatase (BALP), as well as vitamin D levels before and 12 months after surgery. A significant bone mass loss was observed was observed with SG and RYGB, in the lumbar spine and hip, whilst no differences were observed in the radial. The percentage bone mass loss was less in the column and femur after SG than with RYGB, although it did not reach statistical significance, 4.6%+/-4.4 (mean+/-SD) and 6.3%+/-5.4 (mean+/-SD), respectively. At 12 months the Ntx increased for both types of surgery, and the BAP was only increased for SG. SG causes less, although not significant, bone mass loss compared to RYGB.

• Vitamin D deficiency and bone mineral density in postmenopausal women receiving aromatase inhibitors for early breast cancer.

  Authors: Xavier Nogues, Sonia Servitja, Maria Jesus Peña, Daniel Prieto-Alhambra, Rosa Nadal, Leonardo Mellibovsky, Joan Albanell, Adolfo Diez-Perez, Ignasi Tusquets

  Maturitas. 07/2010; 66(3):291-7.

  Aromatase inhibitors (AI) treatment leads to an increased risk of bone loss and fractures. In a group of women with early breast cancer (EBC) and baseline Vitamin D deficiency (<30 ng/ml) who areAromatase inhibitors (AI) treatment leads to an increased risk of bone loss and fractures. In a group of women with early breast cancer (EBC) and baseline Vitamin D deficiency (<30 ng/ml) who are treated with AI, we aim to describe: serum levels of Vitamin D, bone mineral density (BMD), calcium intake, and the increase of serum 25(OH)D accomplished in 3 months of treatment with Vitamin D supplements. Prospective, non-randomized clinical trial. In 232 consecutively included women with EBC in treatment with AI, we assessed baseline calcium intake, serum levels of 25(OH)D, BMD and, spine X-ray. All received Calcium and Vitamin D supplements, and those with vitamin deficiency received 16,000 IU Vitamin D every 2 weeks. Serum levels of 25(OH)D were newly assessed after treatment. All the baseline evaluation was performed before starting AI treatment. Mean age at baseline (+/-SD) was 63.2+/-8.8 years. In 150 (64.9%) cases, the women had been treated previously with tamoxifen; 101 (43.7%) started exemestane, 119 (51.5%) letrozole, and 11 (4.8%) anastrozole. The AI were initiated within 6 weeks after surgery or after the last cycle of chemotherapy. At baseline, 88.1% had 25(OH)D levels <30 ng/ml, 21.2% had severe deficiency (<10 ng/ml), and 25% of the participants had osteoporosis. Mean daily calcium intake was low (841+/-338). We found a significant association between 25(OH)D levels and BMD at baseline, which remained significant in femoral neck BMD after multivariate adjustment. Plasma 25(OH)D levels improved significantly at 3 months follow-up in those treated with high dose Vitamin D supplements: mean increase 32.55 ng/ml (95%CI 28.06-37.03). Our study suggests a high prevalence of commonly unrecognized Vitamin D deficiency in women with EBC treated with AI, a known osteopenic agent. Our results support the need for a routine assessment of 25(OH)D levels and, when necessary, supplementation in these patients.

• Microindentation for in vivo measurement of bone tissue mechanical properties in humans.

  Authors: Adolfo Diez-Perez, Roberto Güerri, Xavier Nogues, Enric Cáceres, Maria Jesus Peña, Leonardo Mellibovsky, Connor Randall, Daniel Bridges, James C Weaver, Alexander Proctor, Davis Brimer, Kurt J Koester, Robert O Ritchie, Paul K Hansma

  Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. 02/2010; 25(8):1877-85.

  Bone tissue mechanical properties are deemed a key component of bone strength, but their assessment requires invasive procedures. Here we validate a new instrument, a reference point indentationBone tissue mechanical properties are deemed a key component of bone strength, but their assessment requires invasive procedures. Here we validate a new instrument, a reference point indentation (RPI) instrument, for measuring these tissue properties in vivo. The RPI instrument performs bone microindentation testing (BMT) by inserting a probe assembly through the skin covering the tibia and, after displacing periosteum, applying 20 indentation cycles at 2 Hz each with a maximum force of 11 N. We assessed 27 women with osteoporosis-related fractures and 8 controls of comparable ages. Measured total indentation distance (46.0 +/- 14 versus 31.7 +/- 3.3 microm, p = .008) and indentation distance increase (18.1 +/- 5.6 versus 12.3 +/- 2.9 microm, p = .008) were significantly greater in fracture patients than in controls. Areas under the receiver operating characteristic (ROC) curve for the two measurements were 93.1% (95% confidence interval [CI] 83.1-100) and 90.3% (95% CI 73.2-100), respectively. Interobserver coefficient of variation ranged from 8.7% to 15.5%, and the procedure was well tolerated. In a separate study of cadaveric human bone samples (n = 5), crack growth toughness and indentation distance increase correlated (r = -0.9036, p = .018), and scanning electron microscope images of cracks induced by indentation and by experimental fractures were similar. We conclude that BMT, by inducing microscopic fractures, directly measures bone mechanical properties at the tissue level. The technique is feasible for use in clinics with good reproducibility. It discriminates precisely between patients with and without fragility fracture and may provide clinicians and researchers with a direct in vivo measurement of bone tissue resistance to fracture.