Low bone mineral density following gastric bypass is not explained by lifestyle and lack of exercise.

BACKGROUND: Bariatric surgery, Roux-en-Y gastric bypass (RYGBP) in particular, is associated with weight loss as well as low bone mineral density. Bone mineral density relies upon multiple factors, some of which are lifestyle factors. The aim of this study was to compare lifestyle factors in order to eliminate them as culprits of the suspected difference in BMD in RYGBP operated and controls. MATERIALS AND METHODS: Study participants included 71 RYGBP-operated women (42.3 years, BMI 33.1 kg/m2) and 94 controls (32.4 years, BMI 23.9 kg/m2). Each completed a DEXA scan, as well as survey of lifestyle factors (e.g. physical activity in daily life, corticosteroid use, and calcium intake). All study participants were premenopausal Caucasian women living in the same area. Blood samples were taken in RYGBP-patients. RESULTS: BMD was significantly lower in RYGBP, femoral neck 0.98 vs. 1.04 g/cm2 compared to controls, despite higher BMI (present and at 20 years of age) and similar physical activity and calcium intake. In a multivariate analysis, increased time since surgery and age were negatively associated with BMD of the femoral neck and total hip in RYGBP patients. CONCLUSION: Despite similar lifestyle, RYGBP was followed by a lower BMD compared to controls. Thus, the reduced BMD in RYGBP cannot be explained, seemingly nor prevented, by lifestyle factors. As the reduction in BMD was associated with time since surgery, strict follow-up is a lifelong necessity after bariatric surgery, and especially important in younger bariatric patients.

Hypoparathyroidism after total thyroidectomy in patients with previous gastric bypass.

PURPOSE: Case reports suggest that patients with previous gastric bypass have an increased risk of severe hypocalcemia after total thyroidectomy, but there are no population-based studies. The prevalence of gastric bypass before thyroidectomy and the risk of hypocalcemia after thyroidectomy in patients with previous gastric bypass were investigated. METHODS: By cross-linking The Scandinavian Quality Registry for Thyroid, Parathyroid and Adrenal Surgery with the Scandinavian Obesity Surgery Registry patients operated with total thyroidectomy without concurrent or previous surgery for hyperparathyroidism were identified and grouped according to previous gastric bypass. The risk of treatment with intravenous calcium during hospital stay, and with oral calcium and vitamin D at 6 weeks and 6 months postoperatively was calculated by using multiple logistic regression in the overall cohort and in a 1:1 nested case-control analysis. RESULTS: We identified 6115 patients treated with total thyroidectomy. Out of these, 25 (0.4 %) had undergone previous gastric bypass surgery. In logistic regression, previous gastric bypass was not associated with treatment with i.v. calcium (OR 2.05, 95 % CI 0.48-8.74), or calcium and/or vitamin D at 6 weeks (1.14 (0.39-3.35), 1.31 (0.39-4.42)) or 6 months after total thyroidectomy (1.71 (0.40-7.32), 2.28 (0.53-9.75)). In the nested case-control analysis, rates of treatment for hypocalcemia were similar in patients with and without previous gastric bypass. CONCLUSION: Previous gastric bypass surgery was infrequent in patients undergoing total thyroidectomy and was not associated with an increased risk of postoperative hypocalcemia.

Hypovitaminosis D and hyperparathyroidism: a 5-year postoperative follow-up of 30,458 gastric bypass and sleeve gastrectomy patients.

BACKGROUND: Bariatric procedures are associated with nutrient deficiencies. Studies show an association between gastric bypass (Roux-en-Y gastric bypass [RYGB]) and hypovitaminosis D as well as hyperparathyroidism, yet few compare RYGB to sleeve gastrectomy (SG), and large long-term analyses are scarce. OBJECTIVE: Evaluate trends of vitamin D and parathyroid hormone (PTH) levels in RYGB and SG. SETTING: National quality register. METHOD: The Scandinavian Obesity Surgery Registry records all bariatric surgeries in Sweden. Data from 2008 to 2021 on primary RYGB or SG with reported 25-hydroxy vitamin D (25-OH-D) and/or PTH levels were included. Individuals with an estimated glomerular filtration rate of <60 mL/min/1.73 m2 were excluded, leaving a study population of 25,385 RYGB and 5073 SG patients. RESULTS: A decrease in 25-OH-D, mirrored by an increase in PTH, was observed after the first year for both procedures, but more pronounced in RYGB. At 5 years, 25-OH-D levels were still higher than at baseline. Regular supplementation resulted in better 25-OH-D and PTH levels. Linear regression found that procedure type (RYGB versus SG), 25-OH-D levels, and time since surgery were significant factors in predicting PTH levels. The risk of pathologic PTH levels (>7 pmol/L) at 2 and 5 years postoperatively was roughly three times higher in RYGB (odds ratios = 3.41 and 2.84, respectively). CONCLUSIONS: Previous studies alongside these results suggest that RYGB, more so than SG, may cause hypovitaminosis D and thereby hyperparathyroidism, which could lead to osteopenia. The threshold for 25-OH-D should be >75 nmol/L, and despite higher levels, current vitamin D supplementation may not be sufficient. Follow-up should include screening for hyperparathyroidism and hypovitaminosis D.

Prospective Evaluation of Complications and Associated Risk Factors in Breast Cancer Surgery.

Background: Surgical site infection (SSI) is a well-known complication after breast cancer surgery. The primary aim was to assess risk factors for SSI. Risk factors for other wound complications were also studied. Materials and Methods: In this prospectively registered cohort study, patients who underwent breast-conserving surgery (BCS) or mastectomy between May 2017 and May 2019 were included. Data included patient and treatment characteristics, infection, and wound complication rates. Risk factors for SSI and wound complications were analyzed with simple and multiple logistic regression. Results: The study cohort consisted of 592 patients who underwent 707 procedures. There were 66 (9.3%) SSI and 95 (13.4%) wound complications. "BMI > 25," "oncoplastic BCS," "reoperation within 24 hour," and "prolonged operative time" were risk factors for SSI with simple analysis. BMI 25-30 and >30 remained as significant risk factors for SSI with adjusted analysis. Risk factors for "any wound complication" with adjusted analysis were "mastectomy with/without reconstruction" in addition to "BMI 25-30" and "BMI > 30." Conclusion: The only significant risk factor for SSI on multivariable analysis were BMI 25-30 and BMI > 30. Significant risk factors for "any wound complication" on multivariable analysis were "mastectomy with/without reconstruction" as well as "BMI 25-30" and "BMI > 30".

Cholecalciferol Injections Are Effective in Hypovitaminosis D After Duodenal Switch: a Randomized Controlled Study.

BACKGROUND: By treating obesity, one of the major epidemics of this past century, through bariatric surgery, we may cause complications due to malnourishment in a growing population. At present, vitamin D deficiency is of interest, especially in patients with inferior absorption of fat-soluble nutrients after biliopancreatic diversion with duodenal switch (BPD/DS). METHODS: Twenty BPD/DS patients, approximately 4 years postoperatively, were randomized to either intramuscular supplementation of vitamin D with a single dose of 600,000 IU cholecalciferol, or a control group. Patients were instructed to limit their supplementation to 1400 IU of vitamin D and to avoid the influence of UV-B radiation; the study was conducted when sunlight is limited (December to May). RESULTS: Despite oral supplementation, a pronounced deficiency in vitamin D was seen (injection 19.3; control 23.2 nmol/l) in both groups. The cholecalciferol injection resulted in elevated 25[OH]D levels at 1 month (65.4 nmol/l), which was maintained at 6 months (67.4 nmol/l). This resulted in normalization of intact parathyroid hormone (PTH) levels. No changes in vitamin D or PTH occurred in the control group. CONCLUSIONS: In BPD/DS patients, having hypovitaminosis D despite full oral supplementation, a single injection of 600,000 IU of cholecalciferol was effective in elevating vitamin D levels and normalizing levels of intact PTH. The treatment is simple and highly effective and thus recommended, especially in cases of reduced UV-B radiation.

Short-Term UVB Treatment or Intramuscular Cholecalciferol to Prevent Hypovitaminosis D After Gastric Bypass-a Randomized Clinical Trial.

BACKGROUND: Gastric bypass is increasingly used worldwide to treat morbidly obese patients with good results. However, several studies have reported low levels of vitamin D in spite of supplementation. In this randomized clinical trial, we have evaluated two principally different interventions, short-term UVB treatment or a single cholecalciferol injection, to prevent hypovitaminosis D. METHODS: Seventy-three patients, randomly treated by UVB (n = 26) or injection (n = 20), and compared to controls (n = 27), were followed for 6 months. Both interventions, 12 treatments of whole-body narrowband UVB and an intramuscular injection of 600,000 IU cholecalciferol, were given in December, when natural sunlight is limited. Blood samples for 25-OH-vitamin D (25[OH]D), intact PTH, calcium, and albumin were obtained at baseline, after 1 and 3 months, and after 6 months for the intervention groups. 25[OH]D was analyzed using a HPLC method. RESULTS: At baseline, 77.2 % of the patients had 25[OH]D <75 nmol/L. At 3 months, both UVB and cholecalciferol injection resulted in significantly higher 25[OH]D levels than controls (71.6 and 77.9 vs. 48.6 nmol/L, p < 0.05). The levels remained rather constant at 6 months (69.0 and 76.7 nmol/L, respectively); however, only injection therapy resulted in improved levels compared to baseline (55.7 nmol/L, p < 0.001). No toxic effects, nor significant changes in PTH or albumin-adjusted calcium, were seen. CONCLUSIONS: In this randomized trial, both interventions, UVB and cholecalciferol, given as an adjunct to oral supplementation in gastric bypass patients, increased the levels of 25[OH]D. Simplicity makes injection therapy suitable for maintaining vitamin D levels during the Nordic winter.

Left-shifted relation between calcium and parathyroid hormone in Graves' disease.

BACKGROUND: Patients with Graves' disease (GD) have disturbances in calcium regulation with manifestations such as postoperative hypocalcemia. We have investigated the thyroid as well as the parathyroid function in detail. MATERIALS AND METHOD: A series of patients undergoing total thyroidectomy for GD (n = 56) or multinodular goiter (MNG; n = 50) were scrutinized for postoperative hypocalcemia and a need for calcium and/or vitamin D substitution. A citrate-calcium (CiCa) clamp was used in 14 patients and 21 controls to quantify the secretion of PTH in relation to the ionized plasma calcium level. The set point, equal to the plasma-ionized calcium concentration at which 50% of the maximal secretion of PTH is inhibited, as well as other CiCa-related parameters were calculated. RESULTS: Hypocalcemia was present in 48% of GD and 41.2% of patients with MNG postoperatively. Patients with GD had lower calcium levels, 18% had serum Ca less than 2.00 mmol/L compared with 4.0% in the MNG group (P = .02). A higher degree of GD patients were given parenteral calcium substitution during the hospital stay (3.6% vs 0 %) and oral calcium substitution at discharge (48% vs 10%), although they had normal vitamin D3 levels. The GD group showed a significantly left-shifted set point compared with the normal group on the CiCa clamp, 1.16 mmol/L vs 1.20 mmol/L (P < .001) as well as an increased PTH release to hypocalcemic stimulus. GD patients also show an association between degree of subclinical toxicosis at time of surgery and risk for developing postoperative hypocalcemia. CONCLUSION: Patients with GD demonstrate dysregulation of the calcium homeostasis by several parameters. GD patients have lower postoperative serum calcium compared with patients with MNG, lower calcium/PTH set point, and a significantly increased release of PTH to hypocalcemic stimulus compared with controls. The CiCa clamp response in GD patients with normal 25-hydroxyvitamin D3 levels mimics that of obese patients in which vitamin D insufficiency has been proposed as an underlying cause.

Left-shifted relation between calcium and parathyroid hormone in obesity.

BACKGROUND: A condition resembling secondary hyperparathyroidism (HPT), including raised levels of PTH and normal levels of serum calcium, has been reported in obesity. A plausible reason may be vitamin D deficiency, but conflicting data have been reported. OBJECTIVE: Our objective was to investigate calcium homeostasis in obese individuals with emphasis on the function of the parathyroid glands. DESIGN AND INTERVENTION: Morbidly obese patients (mean body mass index=46.6+/-6) were examined for their status of calcium homeostasis. A subset was thoroughly investigated with calcium-citrate (CiCa) clamping. PATIENTS: Of 108 morbidly obese patients, 11 underwent CiCa clamping as well as 21 healthy volunteers of normal weight and 15 with primary HPT (pHPT). Large patient cohorts of normal individuals and pHPT patients were also used as comparisons. OUTCOME MEASURES AND RESULTS: All obese individuals had normal serum calcium and creatinine levels. Mean levels of 25-OH-vitamin D3 in serum were low, 53 nmol/liter (reference range 75-250 nmol/liter). Mean intact plasma PTH was 5.1 pmol/liter (reference range 1.1-6.9 pmol/liter). There was a significant positive correlation between PTH and duration of obesity. CiCa clamping in obese subjects revealed a remarkably high sensitivity for calcium and a left-shifted relation between plasma calcium and PTH (set point) compared with the normal population. CiCa clamping in pHPT patients demonstrated a right-shifted PTH-Ca curve. CONCLUSION: Although vitamin D levels in the obese individuals were low, few displayed overt signs of secondary HPT. The CiCa clamping implied a disturbance in the calcium homeostasis comparable to early renal insufficiency, with a left-shifted Ca-PTH curve and a lower set point compared with the normal population.

Association of parathyroid adenoma and pregnancy with preeclampsia.

OBJECTIVE: Case reports have described associations between calcium metabolism disturbances and primary hyperparathyroidism with preeclampsia, suggesting parathyroid involvement in preeclampsia etiology. This study examines whether parathyroid adenoma, the main cause of hyperparathyroidism, diagnosed and treated before pregnancy is associated with preeclampsia. DESIGN: We conducted a register-based study to assess the association between parathyroid adenoma and subsequent preeclampsia. SETTING: Births among Sweden's general population were studied. POPULATION: The study population included 52 women with a diagnosis of parathyroid adenoma and 519 without, all of whom had a subsequent singleton pregnancy between 1973 and 1997. METHODS: We performed a conditional logistic regression investigating the association of parathyroid adenoma with subsequent preeclampsia in the first singleton pregnancy with adjustment for potential confounding factors. MAIN OUTCOME MEASURE: The main outcome was a diagnosis of preeclampsia that does not include women with prior chronic hypertension. To ensure that treatment of parathyroid adenoma was completed before pregnancy, those with a diagnosis of parathyroid adenoma made less than 2 yr before delivery (and the matched comparison women) were excluded. RESULTS: Statistically, parathyroid adenoma prior to delivery is significantly (P < 0.001) associated with preeclampsia, producing an adjusted odds ratio of 6.89 (95% confidence interval, 2.30, 20.58). CONCLUSION: A history of parathyroid adenoma should be viewed as a risk for preeclampsia.