Adequate vitamin D supplementation does not ameliorate bone loss following long limb-biliopancreatic diversion in morbidly obese women.

OBJECTIVES: The objective of this study is to investigate the effect of adequate vitamin D supplementation on bone mineral density (BMD) following long limb-biliopancreatic diversion (LL-BPD), a malabsorptive bariatric operation. BACKGROUND: Marked weight loss following bariatric surgery is associated with significant decrease in BMD, attributed to the weight loss and to nutritional, mineral, and vitamin D deficiencies resulting in secondary hyperparathyroidism. METHODS: Two groups, of 35 and 37 healthy, obese (BMI, 50.4 + 6.6 and 46.5 + 4.8 g/cm2), premenopausal, normally menstruating women underwent LL-BPD. Both groups received high-calcium diets, 600 IU of vitamin D, and 1000 mg elemental calcium daily, while group B received an extra dose of vitamin D (10,000 IU/day) during the first postoperative month, followed by dose adjustment in order to maintain 25OHD concentration higher than 30 µg/L. Areal BMD (aBMD) was measured at the lumbar spine preoperatively and 1 year postoperatively. RESULTS: One year postoperatively, BMI decreased by approximately 19 kg/m2 in both groups, while 25-OH-vitamin D levels did not change in group A (18.7 + 9.1 to 20.2 + 13.0 µg/L, (p = 0.57)) and increased in group B (15.58 ± 5.73 to 52.97 ± 15.46 µg/L, (p = < 0.001). PTH levels increased in group A (from 38.5 ± 12.2 to 51.2 ± 32.8 pg/ml) (p = 0.047) and decreased in group B (from 51.61 ± 18.7 to 45.1 ± 17.8 pg/ml) (p = 0.042). Lumbar spine aBMD decreased similarly in both groups (p = 0.311, for the comparison between groups) from 1.198 + 0.14 to 1.103 + 0.15 g/cm2 in group A (p < 0.001) and from 1.157 + 0.14 to 1.076 + 0.14 g/cm2 in group B (p < 0.001) and Z-score from 0.93 + 0.97 to 0.19 + 1.02, (p < 0.001) and from 1.15 + 1.29 to 0.419 + 1.28, (p < 0.001), respectively. CONCLUSIONS: LL-BPD leads to similar and significant bone mass reduction 1 year postoperatively, irrespective of adequate vitamin D replacement and in the absence of secondary hyperparathyroidism.

Pregnancy outcomes and nutritional indices after 3 types of bariatric surgery performed at a single institution.

BACKGROUND: Nutritional status during pregnancy and the effects of nutritional deficiencies on pregnancy outcomes after bariatric surgery is an important issue that warrants further study. The objective of this study was to investigate pregnancy outcomes and nutritional indices after restrictive and malabsorptive procedures. METHODS: We investigated pregnancy outcomes of 113 women who gave birth to 150 children after biliopancreatic diversion (BPD), Roux-en-Y gastric bypass (RYGB), and sleeve gastrectomy (SG) between June 1994 and December 2011. Biochemical indices and pregnancy outcomes were compared among the different types of surgery and to overall 20-year hospital data, as well as to 56 presurgery pregnancies in 36 women of the same group. RESULTS: Anemia was observed in 24.2% and 15.6% of pregnancies after BPD and RYGB, respectively. Vitamin B12 levels decreased postoperatively in all groups, with no further decrease during pregnancy; however, low levels were observed not only after BPD (11.7%) and RYGB (15.6%), but also after SG (13.3%). Folic acid levels increased. Serum albumin levels decreased in all groups during pregnancy, but hypoproteinemia was seen only after BPD. Neonates after BPD had significantly lower average birth weight without a higher frequency of low birth weight defined as<2500 g. A comparison of neonatal data between babies born before surgery and siblings born after surgery (AS) showed that AS newborns had lower average birth weight with no significant differences in body length or head circumference and no cases of macrosomia. CONCLUSION: Our study showed reasonably good pregnancy outcomes in this sample population after all types of bariatric surgery provided nutritional supplement guidelines are followed. Closer monitoring is required in pregnancies after malabsorptive procedures especially regarding protein nutrition.

Bone mass decreases in morbidly obese women after long limb-biliopancreatic diversion and marked weight loss without secondary hyperparathyroidism. A physiological adaptation to weight loss?

OBJECTIVE: To investigate the effect of marked weight loss after long limb-biliopancreatic diversion (BPD-LL) on bone mass and serum calcium, 25-OH-vitamin D, and PTH levels in relation to calcium supplementation. BACKGROUND DATA: BPD is the most effective type of bariatric surgery, but it is followed by bone mass loss, mainly attributed to calcium and vitamin D malabsorption leading to secondary hyperparathyroidism. METHODS: Two groups, each consisting of 26 healthy, morbidly obese, premenopausal women, underwent BPD-LL. Both groups received high-calcium diets, 200 IU of vitamin D and 100 mg elemental calcium daily and group B, in addition to an extra 2 g of calcium. Bone density and biochemical markers were measured before and 12 months after BPD-LL. RESULTS: One year after surgery, both groups had lost an average of 55 kg of body weight; albumin-corrected calcium concentration did not change. 25-OH-vitamin D levels in group A were 17.34 +/- 8.90 pre- and 20.51 +/- 14.71 microg/L postoperatively (p = 0.058), and in group B, 15.70 +/- 9.46 and 13.52 +/- 8.16 microg/L (p = 0.489), respectively. PTH levels in group A were 38.5 +/- 12.2 before and 51.2 +/- 32.8 pg/ml after surgery (p = 0.08), and in group B, 48.1 +/- 26.3 and 52.9 +/- 29.2 pg/ml (p = 0.147), respectively. Bone formation markers (alkaline phosphatase, osteocalcin and procollagen type 1), as well as the bone resorption marker CTx, increased significantly in both groups. Bone mineral density T score was 0.862 +/- 0.988 in group A and 0.851 +/- 1.44 in group B and declined postoperatively to -0.123 +/- 1.082 and 0.181 +/- 1.285, respectively. CONCLUSIONS: Marked weight loss after BPD-LL leads to increased bone turnover and normalization of the increased bone mass without calcium or vitamin D malabsorption and without the appearance of secondary hyperparathyroidism. We conclude that the bone mass reduction is a normal adaptation to the decreased loading of the bone following weight loss.

Combined growth hormone-releasing hormone and growth hormone-releasing peptide-6 test for the evaluation of growth hormone secretion in children with growth hormone deficiency and growth hormone neurosecretory dysfunction.

BACKGROUND: The combined growth hormone-releasing hormone and growth hormone-releasing peptide-6 (GHRH + GHRP-6) test is most potent in evaluating GH secretion. AIMS: To assess its capability in children with GH deficiency and low spontaneous GH secretion (GH neurosecretory dysfunction). METHODS: 35 children with GH <10 microg/l after levo-dopa/clonidine (GHD), 15 with normal provocative tests but abnormal 24-hour spontaneous GH secretion (GHND), and 20 controls (C) were given 1 microg/kg of GHRH and GHRP-6 i.v. and GH (microg/l) was measured at -15, 0, 5, 10, 15, 30, 45 and 60 min. RESULTS: Six were nonresponders to the combined test, with significantly lower peak GH 20.7 (7.8-31.8) than C and the rest of the patients (responders). Peak GH was similar between prepubertal (PP) controls 167 +/- 88, GHD 202 +/- 110 and GHND 155 +/- 83. Pubertal (P) controls had higher peak GH 328 +/- 149 than P-GHD 203 +/- 105 and P-GHND 186 +/- 105. While P-C had higher peak GH than PP-C, PP and P children had similar responses within the GHD and GHND groups. CONCLUSIONS: The GHRH + GHRP-6 test detects children with severe GH insufficiency. Patients with GHD respond similarly to those with GHND, indicating a possible hypothalamic GH neuroregulatory dysfunction in GHD. Responders to the combined test may be eligible for treatment with a synthetic GH secretagogue.