Low lumbar spine bone mineral density in both male and female endurance runners

There have been many reports of low bone mineral density (BMD) in female endurance runners. Although there have been several reports of low BMD in male runners, it is unclear how comparable the problem is to that in females. We compared BMD between male and female endurance runners and with a reference population. One hundred and nine endurance runners (65 females, 44 males) aged 19-50 years participated and had been training regularly for at least 3 years (32-187.2 km week(-1)) in events from 3 km to the marathon. BMD was measured at the lumbar spine (L2-L4) and hip by DXA. A questionnaire assessed training and menstrual status. Lumbar spine T scores were similar in male and female runners (-0.8 (0.8) versus -0.8 (0.7); f = 0.015; P = 0.904) as were total hip T scores (0.6 (7.9) versus 0.5 (9.2); f = 0.192; P = 0.662). The proportion of male runners with low lumbar spine BMD (<-1.0) (n = 16 from 44) compared to that of females (n = 27 from 65) (P = 0.675). Males had lower spine T scores than eumenorrhoeic females (-0.8 (0.7) versus -0.4 (0.7); f = 5.169; P = 0.03). There were moderate negative correlations between weekly running distance and lumbar spine BMD in males and females (r(2) = 0.267; 0.189; P < 0.001), independent of menstrual status in females (r(2) = 0.192; P < 0.001). Lumbar spine but not hip T scores were greater in runners who participated in resistance training at least twice-a-week (male: -0.4 versus -1.1; female: -0.5 versus -1.1; P < 0.01). Using multiple regression, running distance (-) and BMI (+) together best predicted lumbar spine T scores (r(2) = 0.402; P < 0.01) in females. Although weak, BMI (+) best predicted hip T scores (r(2) = 0.167; P < 0.05). In males, running distance and training years (-) together best predicted lumbar spine T scores (r(2) = 0.400; P < 0.01). Training years (-) best predicted hip T scores (r(2) = 0.361; P < 0.01). To conclude, our findings suggest that male runners face the same bone threat at the spine, as female runners. Further research in male athletes is required. Incorporation of regular resistance training into an athlete's training programme may be a useful preventative strategy.     

Solute-free versus electrolyte-free water clearance in the analysis of osmoregulation

Reduced bone mineral density (BMD) and an increased risk of vertebral fracture have been reported in calcium-stone-forming (CSF) patients presenting with idiopathic hypercalciuria. We investigated the association between BsmI vitamin D receptor (VDR) polymorphism and BMD in 68 hypercalciuric CSF patients (35 males and 33 premenopausal females, mean age +/- SD = 39 +/- 10 years). BMD was measured at lumbar spine (L2-L4) and femur neck sites using dual energy X-ray absorptiometry. A 72-hour dietary record and a 24-hour urine sample were obtained from each patient to determine calcium intake and excretion. The allelic frequency found for the sample as a whole was 16% BB, 44% Bb and 40% bb. Mean BMD values did not significantly differ among BB, Bb and bb patients at L2-L4 (1.162 +/- 0.10, 1.133 +/- 0.11 and 1.194 +/- 0.19 g/cm2, mean +/- SD, respectively) or at neck sites (0.920 +/- 0.11, 0.931 +/- 0.15 and 0.982 +/- 0.15 g/cm2, respectively). Calcium intake and excretion were also not significantly different among the three genotypes. Patients were then divided into two groups, normal BMD, T-score > or =-1 (n = 34) and low BMD, T-score <-1 (n = 34), to further evaluate the allele influence on previous bone loss. Despite a trend for a higher mean BMD at spine or neck sites for patients with one or two b alleles when compared to BB patients, the difference did not reach statistical significance. The distribution of BB, Bb and bb genotypes in the low-bone-mass group (15, 47 and 38%, respectively) was similar to that in the normal-bone-mass group (18, 41 and 14%, respectively). These data suggest that BsmI VDR polymorphism does not play an important role in the bone loss seen in hypercalciuric CSF patients.     

Impaired vasoreactivity despite an increase in plasma nitrite in patients with abdominal aortic aneurysms

OBJECTIVE: This investigation was designed to determine whether differences in vasoreactivity occur in patients with abdominal aortic aneurysms (AAAs) as compared with patients with peripheral arterial occlusive disease (PAOD) or individuals (controls) without known vascular disease. METHODS: Brachial artery vasoreactivity was assessed in a blinded fashion, after endothelium-dependent (ED) and endothelium-independent (EI) flow-mediated vasodilation, in age-matched, male patients with AAAs (n = 11) or PAOD (n = 9) or in controls (n = 10). There were no significant differences in prestudy systolic or diastolic blood pressure, body mass index, or antilipidemic medications among the groups studied. Exclusion criteria included diabetes and tobacco use within 3 months. Quantitative ultrasound scan measurements of brachial artery diameters were performed at rest and after either forearm ischemia (ED) or administration of 0.4 mg sublingual nitroglycerin (EI). Plasma nitric oxide (NO(X) = NO(2) + NO(3)) was measured with the Saville assay. Asymmetric dimethylarginine, an endogenous inhibitor of NO(X) synthase, was measured with liquid chromatography. RESULTS: Initial brachial artery diameters were not significantly different among the groups studied (4.85 +/- 0.18 mm for AAA group, 4.82 +/- 0.17 mm for PAOD group, 4.68 +/- 0.20 mm for controls). ED and EI vasodilation was significantly less (P =.02 and.03, respectively) in the AAA group (-1.71 +/- 1.52 and 8.33 +/- 1.13, respectively) when compared with the controls (2.96 +/- 1.04 and 13.88 +/- 2.16, respectively). However, plasma NO(X) was significantly increased (P =.01) in the AAA group (7.86 +/- 0.85 micromol/L) as compared with both controls (5.13 +/- 0.63 micromol/L) and PAOD (4.85 +/- 0.46 micromol/L). Asymmetric dimethylarginine levels were decreased in the AAA group (0.34 +/- 0.05 micromol/L) as compared with the PAOD group (0.46 +/- 0.09 micromol/L). No correlation existed between aneurysm size and ED or EI vasodilation or plasma NO(X). CONCLUSION: This study is the first to document a divergence between ED and EI vasoreactivity and systemic NO metabolites in patients with AAAs. It is speculated that a dysfunctional vessel wall response, rather than a lack of NO, may be important in the pathogenesis of AAAs.     

Dental malocclusion is associated with reduced systemic bone mineral density in adolescents.

There is no published data about associations between the state of dentition and bone mass in adolescents. The objective of this study was to investigate whether the prevalence of caries and dental malocclusion is associated with bone mass during growth. In 123 healthy Caucasian subjects (72 males, 51 females) aged 14-18 yr, DMFT figures (decayed teeth, missing teeth, filled teeth) and presence of malocclusion, according to Angle classification, were determined. Participants completed a questionnaire regarding dental hygiene, physical activity level, and consumption of sweets. Anthropometry and pubertal stages were examined. Bone mineral density (BMD) was examined using dual energy X-ray absorptiometry (DXA) in the total body, head, and lumbar spine. No association was found between DMFT (mean+/-SD: 8.33+/-3.9) and BMD or Z-scores for BMD. Malocclusion was found in 49 subjects (39.8%) and was more prevalent in females than males. Malocclusion was associated with lower total BMD independently of body size (p=0.001; Z-scores: -0.21+/-0.27 vs +0.33+/-0.17; p=0.1) in males (but not females), producing odds ratio 1.6 (95% confidence interval: 1.09-2.34%; p=0.02). Head BMD was also lower in the males with malocclusion than in those without (p=0.004). Neither caries nor the tooth loss appear to be associated with BMD during growth. Boys with malocclusion are at higher risk of reduced BMD. This suggests that inadequate bone mass accrual in males coexists with impaired growth of the masticatory system in childhood and adolescence, however, the causal pathway is unknown. Factors that produce malocclusion may also affect bone mass or size but further prospective studies are needed to evaluate the relationship.     

Differential effects of growth hormone therapy in malnourished hemodialysis patients

BACKGROUND: Malnutrition is common in chronic hemodialysis patients and is associated with increased morbidity and mortality. Several factors such as metabolic acidosis, hyperparathyroidism, and insulin as well as growth hormone (GH) resistance may lead to enhanced protein catabolism. Recombinant human growth hormone (rhGH) has been proposed as treatment of malnutrition because of its anabolic effects. METHODS: In the present placebo-controlled, double blind study, the effects of three months of rhGH therapy on nutritional and anthropometric parameters, on bone metabolism and bone mineral density (BMD), as well as on polymorphonuclear leukocyte (PMNL) function and quality of life (QoL) were evaluated in 19 malnourished hemodialysis patients (10 females and 9 males) with a mean age of 59.3 +/- 13.4 years. RhGH (0.125 IU/kg) was given three times a week during the first four weeks and 0.25 IU/kg thereafter three times a week after each dialysis session. RESULTS: Insulin-like growth factor I (IGF-I) concentration rose significantly from 169.2 +/- 95.6 ng/mL to 262.9 +/- 144.4 ng/mL (p< 0.01) in the group receiving rhGH. Albumin, prealbumin, transferrin, cholesterol, high-density lipoprotein (HDL) cholesterol, cholinesterase, predialytic creatinine, and blood urea nitrogen showed no significant changes during the three months in both groups. Total body fat (%TBF) was slightly reduced after three months (P = NS) in the patients receiving GH, whereas lean body mass (LBM) remained stable during therapy. Procollagen I carboxy terminal peptide (PICP), a marker of bone formation, increased significantly after three months from 250.1 +/- 112.6 to 478.5 +/- 235.2 microg/L (P < 0.01) in the GH-treated patients, whereas parameters of bone resorption like telopeptide ICTP showed only a slight increase (50.3 +/- 18.5 vs. 70.0 +/- 39.5 microg/L, P = NS). BMD at the lumbar spine decreased significantly after three months in the treatment group (0.8 +/- 0.17 vs. 0.77 +/- 0.16 g/cm2, P < 0.01), whereas BMD at the femoral neck remained stable in both groups. Phagocytic activity of PMNLs increased significantly after three months of therapy with rhGH, whereas other parameters of PMNL function were not affected by GH. QoL was slightly improved in the GH treated group, but decreased markedly in the placebo group. CONCLUSIONS: Three months of treatment with rhGH in malnourished patients on chronic hemodialysis causes a significant increase in IGF-I levels without significant changes in nutritional and anthropometric parameters. In contrast, bone turnover was enhanced with an initial decrease in BMD at the lumbar spine, and phagocytic activity of PMNLs was increased.     

成人阻塞性睡眠呼吸暂停低通气综合征与骨密度降低及骨质疏松相关性的Meta分析

目的探讨阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea-hypopnea syndrome,OSAHS)与骨密度降低及骨质疏松之间的相关性。方法从PubMed、EMBASE、Web of Science、the Cochrane Library、中国生物医学文献数据库(CBM)、中国知网(CNKI)、万方数据库(Wanfang data)和维普数据库(VIP)检索OSAHS与骨密度及骨质疏松相关性的研究。采用纽卡斯尔-渥太华量表(the Newcastle-Ottawa scale,NOS)对纳入研究进行质量评价。所有数据的合并、亚组分析采用Review manager 5.3软件,敏感性分析和发表偏倚检测采用Stata 15.1软件。结果检索到1091篇文献,1074篇文献被排除,17篇全文文献里的17项研究所包含的113460位研究对象的数据被提取。OSAHS组与对照组相比,骨质疏松症的发生率高(OR=1.74,95%CI:1.43~2.13,P<0.00001);性别、年龄的亚组分析显示,男性(OR=1.90,95%CI:1.33~2.72,P=0.0004)、女性(OR=2.56,95%CI:1.96~3.34,P<0.00001)、大于65岁老年人(OR=2.62,95%CI:1.86~3.71,P<0.00001)、40~65岁中年人(OR=1.73,95%CI:1.31~2.28,P=0.0001)骨质疏松症的发生率均高。OSAHS组与对照组相比,腰椎骨密度显著降低(MD=-0.12,95%CI:-0.18~-0.06,P=0.0001)。性别的亚组分析显示,男性腰椎骨密度显著降低(一般人群:MD=-0.08,95%CI:-0.15~-0.01,P=0.02;无伴随疾病人群:MD=-0.12,95%CI:-0.19~-0.05,P=0.0008);女性腰椎骨密度略低(MD=-0.08,95%CI:-0.21~0.06,P=0.27),但差异无统计学意义。OSAHS组与对照组相比,股骨颈骨密度显著降低(MD=-0.12,95%CI:-0.19~-0.05,P=0.0007)。男性亚组股骨颈骨密度显著降低(一般人群:MD=-0.09,95%CI:-0.17~-0.02,P=0.02,无伴随疾病人群:MD=-0.11,95%CI:-0.19~-0.03,P=0.006);女性亚组股骨颈骨密度略低(MD=-0.10,95%CI:-0.33~0.12,P=0.37),但差异无统计学意义。各项分析纳入的研究无明显发表偏倚。结论OSAHS组与对照组相比,骨质疏松症的发生率高,腰椎骨密度、股骨颈骨密度均有所降低。     

Better preservation of endothelial function and decreased activation of the fetal renin-angiotensin pathway with the use of pulsatile flow during experimental fetal bypass

OBJECTIVE: Pulsatile flow was shown to overcome the progressive rise in peripheral and placental vascular resistances observed during steady-flow bypass, this rise being counteracted by inhibition of nitric oxide synthase. This study quantifies the release of endothelial vasoactive substances during a 60-minute in utero model of fetal bypass. METHODS: Fetuses were randomly allocated into 1 of 2 groups (steady flow, n = 8, or pulsatile flow, n = 13) and subjected to bypass through central cannulation and perfusion with either a centrifugal or pulsatile (125 beats x min(-1)) blood pump. RESULTS: Lactate concentration was high, starting at fetal exteriorization and increasing during fetal preparation in the 2 groups. Once bypass was established, the rise was significant only in the steady-flow group. Plasma nitric oxide metabolites, similar before bypass, reached higher levels during pulsatile flow at the end of bypass (99+/-9 vs. 82+/-23 micromol x L(-1); P =.037). Levels of urinary nitric oxide metabolites were significantly higher in the pulsatile-flow than in the steady-flow group (764+/-143 vs. 508+/-240 micromol x L(-1); P =.005). Plasma cyclic guanosine monophosphate levels increased after 30 minutes of bypass in the pulsatile-flow group (25+/-18 vs. 12+/-8 pmol x mL(-1); P =.004), and urinary cyclic guanosine monophosphate excretion was higher in the pulsatile-flow group (517+/-450 vs. 118+/-78 pmol x mL(-1); P =.024). Plasma endothelin-1 levels increased in the 2 groups and were higher in the steady-flow group at 30 minutes (27+/-5 vs. 23+/-2 pg x mL(-1); P =.04) and 60 minutes of bypass (39+/-7 vs 32 +/- 6 pg x mL(-1); P =.04). Plasma renin concentration increased significantly during bypass only in the steady-flow group (26+/-10 vs. 57+/-42 in ng A1 x mL(-1) x h(-1); P =.04). CONCLUSIONS: Improved placental and peripheral perfusion during fetal pulsatile-flow bypass may be mediated by preservation of fetal/maternal endothelial nitric oxide biosynthetic mechanisms and/or decreased activation of the fetal renin-angiotensin pathway.     

Leukocyte-depleted terminal blood cardioplegia provides superior myocardial protective effects in association with myocardium-derived nitric oxide and peroxynitrite production for patients undergoing prolonged aortic crossclamping for more than 120 minutes

OBJECTIVES: This study was designed to examine the myocardial protective effect of leukocyte-depleted terminal blood cardioplegia in association with nitric oxide and peroxynitrite production, especially for patients undergoing prolonged aortic crossclamping. METHODS: Fifty-four patients (34 men, 20 women, mean age 56.7 +/- 12.7 years) undergoing aortic valve replacement were randomly allocated to one of two groups; group LDTC (n = 27) received 10 minutes of leukocyte-depleted terminal blood cardioplegic solution, and group CONT (n = 27) served as controls. Each group was subdivided into 2 groups: aortic crossclamping for less than 120 minutes in groups LDTC-S (n = 13) and CONT-S (n = 14); aortic crossclamping for 120 minutes or more in groups LDTC-L (n = 14) and CONT-L (n = 13). RESULTS: After aortic unclamping, group LDTC-L showed higher incidence of spontaneous defibrillation (78.6% vs 30.8%, P =.0213), higher plasma nitrate + nitrite in the coronary sinus effluent (32.5 +/- 4.1 vs 28.7 +/- 3.0 micromol/L, P =.0013), lower differences between coronary sinus effluent and arterial blood in the percentage ratio of nitrotyrosine to tyrosine (myocardium-derived peroxynitrite; 2.987% +/- 0.576% vs 3.951% +/- 0.952%, P =.0036), and plasma polymorphonuclear-elastase (113.9 +/- 21.3 vs 155.5 +/- 41.6 microg/L, P =.0029) and malondialdehyde (2.75 +/- 0.67 vs 4.02 +/- 0.96 micromol/L, P =.0005) than group CONT did. Postoperatively, group LDTC-L showed lower human-heart fatty acid-binding protein (111.4 +/- 25.2 vs 156.4 +/- 38.6 IU/L, P =.0013), lower creatine kinase-muscle and brain (19.2 +/- 4.7 vs 24.8 +/- 6.5 IU/L, P =.0120), and smaller requirement of catecholamine (5.44 +/- 2.29 vs 8.45 +/- 3.42 microg x kg(-1) x min(-1), P =.0122). There were no significant differences in these parameters between groups LDTC-S and CONT-S. CONCLUSIONS: This study demonstrated that leukocyte-depleted terminal blood cardioplegia provided superior myocardial protective effects and regulated myocardial-derived nitric oxide and peroxynitrite production only for patients undergoing aortic crossclamping for more than 120 minutes. The results suggest that prolonged aortic crossclamping deteriorates the tolerance to leukocyte-mediated myocardial injury accompanied by endothelial dysfunction associated with nitric oxide and peroxynitrite production.     

Early and late outcome of cardiac surgery in patients with liver cirrhosis.

Liver cirrhosis is a major risk factor in general surgery. Few studies have reported on the outcome of cardiac surgery in these patients. Herein we report our recent experience in this high-risk patient population according to the Child-Turcotte-Pugh classification and Model for End-Stage Liver Disease (MELD) score. Between January 1998 and December 2004, 27 patients (mean age 58 +/- 10 yr, 20 male) with cirrhosis who underwent cardiac surgery were identified. Patients were in Child-Turcotte-Pugh class A (n = 10), B (n = 11), and C (n = 6) and mean MELD score was 14.2 +/- 4.2. Operative mortality was 26% (n = 7). Stratified mortality according to Child-Turcotte-Pugh class was 11%, 18%, and 67% for class A, B, and C, respectively. No mortality occurred in patients who had revascularization without the use of cardiopulmonary bypass (n = 5). The 1-yr survival was 80%, 45%, and 16% for Child-Turcotte-Pugh class A, B, and C, respectively (P = 0.02). Major postoperative complications occurred in 22%, 56%, and 100% for Child-Turcotte-Pugh class A, B, and C, respectively. Child-Turcotte-Pugh classification was a better predictor of hospital mortality (P = 0.02) compared to MELD score (P = 0.065). In conclusion, our results suggest that cardiac surgery can be performed safely in patients with Child-Turcotte-Pugh class A and selected patients with class B. Operative mortality remains high in class C patients. Careful patient selection is critical in order to improve surgical outcome in patients with cirrhosis.     

Does tranexamic acid reduce desmopressin-induced hyperfibrinolysis?

OBJECTIVE: Desmopressin releases tissue-type plasminogen activator, which augments cardiopulmonary bypass--associated hyperfibrinolysis, causing excessive bleeding. Combined use of desmopressin with prior administration of the antifibrinolytic drug tranexamic acid may decrease fibrinolytic activity and might improve postoperative hemostasis. METHODS: This prospective randomized study was carried out with 100 patients undergoing coronary artery bypass operations between April 1999 and November 2000 in Gülhane Military Medical Academy. Patients were divided into 2 groups. Desmopressin (0.3 microg/kg) was administrated just after cardiopulmonary bypass and after protamine infusion in group 1 (n = 50). Both desmopressin and tranexamic acid (before the skin incision at a loading dose of 10 mg/kg over 30 minutes and followed by 12 hours of 1 mg.kg(-1).h(-1)) were administrated in group 2 (n = 50). RESULTS: Significantly less drainage was noted in group 2 (1010 +/- 49.9 mL vs 623 +/- 41.3 mL, P =.0001). Packed red blood cells were transfused at 2.1 +/- 0.5 units per patient in group 1 versus 0.9 +/- 0.3 units in group 2 (P =.0001). Fresh frozen plasma was transfused at 1.84 +/- 0.17 units per patient in group 1 versus 0.76 +/- 0.14 units in group 2 (P =.0001). Only 24% of patients in group 2 required donor blood or blood products compared with 74% of those in the isolated desmopressin group (group 1, P =.00001). Group 1 and group 2 findings were as follows: postoperative fibrinogen, 113 +/- 56.3 mg/dL versus 167 +/- 45.8 mg/dL (P =.0001); fibrin split product, 21.2 +/- 2.3 ng/mL versus 13.5 +/- 3.4 ng/mL (P =.0001); and postoperative hemoglobin level, 7.6 plus minus 1.2 g/dL versus 9.1 plus minus 1.2 g/dL (P =.0001). CONCLUSION: Tranexamic acid administration significantly reduces desmopressin and bypass-induced hyperfibrinolysis. Combined use of tranexamic acid and desmopressin decreases both postoperative blood loss and transfusion requirement.     

Bone mineral density in adults transplanted in childhood for liver disease

INTRODUCTION: It remains unclear whether bone mineral density (BMD) is compromised in adult life after liver transplantation (LT) during childhood. METHODS: This was a cross-sectional study of total body (TB) and lumbar spine (LS) dual-energy X-ray absorptiometry, anthropometry, and data collected, which included a physical activity questionnaire. RESULTS: Fifteen patients were enrolled. Mean age at LT was 10.6 (4.5) years (range 1.6 to 18.4). The mean posttransplant period was 12.0 (4.1) years (range 4.4 to 16.7); six were men. The mean TB BMD, 1.11 (0.12) g/cm2, was similar to LS BMD, 1.15 (0.17) g/cm2 (P=.82). The Z-score mean was lower for TB BMD, -0.92 (1.2), and LS BMD, -0.41 (1.2) (P=.22). There was no effect from gender, pretransplant cholestasis (9/15 cases), age at LT, and time since LT. BMD (Z-score) was better for those on corticosteroids (9/15 cases): TB BMD -0.42 (1.20) versus -1.77 (0.86) (P=.04); LS BMD 0.14 (1.00) versus -1.54 (1.03) (P=.03). Anthropometry Z-scores were height -0.04 (0.70), weight -0.33 (0.39), and BMI -0.32 (0.37). There was no correlation between Z-scores for BMD and any of the anthropometry parameters. CONCLUSION: Although the mean TB BMD was lower in transplanted patients than would be expected for the general population, overall BMD and anthropometry were with the normal adult ranges for adults who had undergone LT in childhood.     

体重、身高对成都地区青壮年腰椎、髋部骨量的影响

目的　研究体重、身高对青壮年腰椎、髋部骨量的影响。方法　随机抽取成都地区年龄在 2 0～ 39岁 ,排除心肝肺肾、内分泌等慢性病、骨代谢疾病及脊椎畸形者 2 37名 (其中男性 10 8名 ,女性 12 9名 ) ,采用美国Lunar公司生产DPX L型双能X线骨密度仪测定受试者腰椎和髋部的骨矿含量 (BMC)、面积 (AREA)、骨密度 (BMD)。全部资料输入微机 ,用SPSS软件进行统计学处理。结果　体重、身高、体重指数 (BMI)与腰椎、髋部的BMC、Area、BMD呈正相关 ,其中体重与腰椎、髋部的BMC、Area中等程度相关 (r=0 39～ 0 5 5 ,P <0 0 1) ,身高与腰椎 (L2 - 4)AREA相关性最好 (r=0 75 8,P <0 0 1) ,体重、身高与BMD相关性差 (r=0 15 2～ 0 2 2 5 ,P <0 0 5 )。男性腰椎及髋部的BMC、AREA均明显高于同年龄组女性 (P <0 0 1) ,男、女L2 - 4BMD无显著性差异 (P >0 0 5 ) ,男性略低于女性。L2 - 4BMC与体重比值及L2 - 4AREA与体重比值 ,男、女无显著性差异 (P >0 0 5 )。L2 - 4Area与身高比值男性明显高于女性 (P <0 0 1)。结论　体重对青壮年BMC的影响大于身高 ,身高对L2 - 4AREA影响最大 ,男、女体重、身高的差异决定了峰值骨量的差异。BMC、Area、BMD 3项指标中 ,BMC更能反映体重、身高的差异 ,用BMC诊断骨质疏松     

Genetic analysis of glucose tolerance in inbred mouse strains. Evidence for polygenic control

To determine genetic factors involved in diabetes susceptibility in inbred strains of mice, we initially evaluated differences in fed plasma glucose and insulin concentrations among six strains (AKR/J, C3H/HeJ, C57BL/6J, C57L/J, DBA/2J, and SWR/J). There was considerable variation in fed plasma glucose concentration, with C3H/HeJ mice the most glucose tolerant (174 +/- 7 mg/dl) and C57BL/6J mice the least glucose tolerant (252 +/- 7 mg/dl, P less than .0001 vs. C3H/HeJ mice). Glycosylated hemoglobin of C57BL/6J mice (4.0 +/- 0.06%) was also higher than that of C3H/HeJ mice (3.52 +/- 0.06%, P less than .0001). The fed plasma insulin concentration did not differ between these two strains. Glucose tolerance was further evaluated in overnight-fasted C3H/HeJ and C57BL/6J mice by an intraperitoneal glucose tolerance test (IPGTT). Although fasting plasma glucose did not differ, the most remarkable difference in plasma glucose during IPGTT between C57BL/6J and C3H/HeJ mice was noted at 30 min (489 +/- 29 vs. 227 +/- 20 mg/dl, P less than .001). To determine the number of genes involved in the phenotypic difference in glucose tolerance, C57BL/6J males were crossed with C3H/HeJ females (F1, C3H/HeJ X C57BL/6J), and the F1 hybrid females were backcrossed with C57BL/6J males (backcrossed, F1 X C57BL/6J). Plasma glucose after 30 min on IPGTT was 219 +/- 8 (n = 21), 456 +/- 18 (n = 23), and 292 +/- 13 (n = 23) mg/dl for C3H/HeJ, C57BL/6J, and F1 mice, respectively (P less than .001 for all comparisons).(ABSTRACT TRUNCATED AT 250 WORDS)     

Lumbar bone mineral density after kidney transplantation: a three-year prospective study

Osteopenia is a common complication after transplantation. However, prospective long-term studies are scarce and most were performed in patients on cyclosporine and high-dose steroids. In 65 patients with functioning grafts, 41 males and 24 females, 50 on tacrolimus-based immunosuppression and 15 on cyclosporine-based immunosuppression, bone mineral density (BMD) was measured in the lumbar spine (L2-L4) and femoral neck (FN) using dual X-ray absorptiometry (DEXA) in the first month after transplantation (baseline) and at 1, 2, and 3 years. At baseline, BMD was similar to the control population both in L2-L4 (z score = -0.421) and in FN (z score = -0.518). During the follow-up, 3 types of patterns were identified: BMD increased in L2-L4 in 25 patients (38.5%), remained stable in 20 patients (30.8%), and decreased in 20 patients (30.8%). BMD losses appeared mainly during the first year (0.964 +/- 0.162 baseline; 0.904 +/- 0.161 at 1 year, 0.886 +/- 0.140 at 3 years; analysis of variance [ANOVA] P < .001). However, the improvement was maintained throughout the follow-up (0.860 +/- 0.176 g/cm2 at baseline; 0.901 +/- 0.161 at 1 year; 0.954 +/- 0.178 at 3 years; ANOVA P < .001) and there was a parallel increase of BMD in FN (0.712 +/- 0.144 at baseline; 0.744 +/- 0.249 at 1 year; 0.826 +/- 0.184 at 3 years; ANOVA P < .01). There were no differences between both groups in graft function, intact parathyroid hormone (iPTH) levels, number of postmenopausal women, or steroid doses. About one third of patients had bone loss during the first year after transplantation. We were unable to identify any risk factor for this complication in patients on low-dose steroids.     

Predicting long-term functional results after myocardial revascularization in ischemic cardiomyopathy

OBJECTIVE: The goal of the present study was to define the early and late functional results after revascularization in ischemic cardiomyopathy and to identify variables predictive of a favorable outcome. METHODS: A retrospective review of all consecutive patients with ischemic cardiomyopathy undergoing myocardial revascularization between January 1991 and June 1998 was undertaken. One hundred sixty-seven patients (140 men) aged 60 +/- 8 years (range, 39-77 years) with angina (n = 107), congestive heart failure (n = 54), or silent ischemia (n = 6) were identified. One hundred six (63%) patients with angina were in Canadian Cardiovascular Society class III or IV, and 40 (24%) patients with congestive failure were in New York Heart Association class III or IV. The preoperative left ventricular ejection fraction averaged 0.28 +/- 0.05 (range, 0.16-0. 30). Thirteen (8%) patients required preoperative mechanical life support. A mean of 2.9 +/- 0.9 grafts per patient were performed, with an average myocardial ischemia time of 53 +/- 23 minutes and bypass time of 104 +/- 31 minutes. RESULTS: There were 3 (1.7%) early deaths and 21 (13%) deaths during follow-up (2.7 +/- 2.1 years; range, 0.3-7.8 years), producing a survival of 94% +/- 2% and 75% +/- 10% at 1 and 5 years, respectively. Despite a significant increase in left ventricular ejection fraction (0.28 +/- 0.05 vs 0. 38 +/- 0.09, P =.0001), only 89 (54%) patients were symptom-free at follow-up. Freedom from recurrent angina was 98% +/- 1% and 81% +/- 8%, whereas freedom from congestive failure was 78% +/- 11% and 47% +/- 20% at 1 and 5 years, respectively. Follow-up New York Heart Association class in patients with congestive failure was improved (40/54 class III-IV vs 11/54 class III-IV, P =.0001). Multivariate analysis showed a lower ejection fraction (P =.01), preoperative congestive failure (P =.03), and a need for preoperative intra-aortic balloon pumping (P =.03) to be associated with a greater prevalence of recurrent congestive failure, whereas male sex (P =.01), preoperative angina (P =.04), use of the internal thoracic artery (P =.03), and higher number of grafts (P =.01) were associated with lower prevalence. Male sex (P =.06), higher number of grafts (P =.04), and shorter duration of myocardial ischemia (P =. 04) were also predictive of improvement in New York Heart Association class at follow-up. CONCLUSIONS: Despite satisfactory early and late survival, late functional outcome after myocardial revascularization in ischemic cardiomyopathy remains suboptimal because of recurrence or persistence of congestive failure. Selection of appropriate surgical candidates and extensive use of complete revascularization with the internal thoracic artery may substantially improve functional results.     

中老年男性及绝经后女性2型糖尿病患者SUA/CR与BMD、BTMs的相关性

目的 回顾性研究中老年男性及绝经后女性2型糖尿病（type 2 diabetes mellitus,T2DM）患者血尿酸肌酐比（SUA/CR）与骨代谢标志物及骨密度（bone mineral density,BMD）的关系。方法 纳入在我院住院的T2DM 患者668例,将中老年男性依据SUA/CR水平进行三分位分组,依次分为M1组、M2组、M3组;绝经后女性依据SUA/CR水平进行三分位分组依次分为F1组、F2组、F3组。结果 ①中老年男性与绝经后女性SUA/CR水平越高,骨质疏松（osteoporosis,OP）或骨量减少比例越低;②中老年男性中,M1组股骨颈BMD最低,1型胶原C端交联肽（CTX）、骨钙素（N-OC）最高（P＜0.05）;绝经后女性中,F3组患者大转子、股骨颈、腰椎1～4（L1～4）、Ward’s三角BMD最高;F1组N-OC、CTX最高（P＜0.05）;③中老年男性SUA/CR与股骨颈BMD正相关,与N-OC、CTX、总1型胶原N端延长肽（P1NP）负相关（P＜0.05）;绝经后女性SUA/CR与L1～4、股骨颈、大转子、Ward’s三角BMD及VD正相关,与N-OC、P1NP、CTX负相关（P＜0.05）;④Logistic回归分析显示SUA/CR是OP或骨量减少的保护性因素。结论 高水平SUA/CR是中老年男性及绝经后女性T2DM患者OP及骨量减少的保护性因素。     

Treatment of established bone loss after renal transplantation with etidronate

BACKGROUND: Osteoporosis is a well-documented complication of organ transplantation. Bisphosphonates have been shown to be effective in preventing corticosteroid-induced osteoporosis in renal transplant recipients, but data are lacking for treatment of established osteoporosis. This study reports our clinical experience of treatment with the bisphosphonate etidronate in a single renal transplant center. METHODS: To establish the effectiveness of etidronate in treating established low bone mineral density (BMD), all newly transplanted patients treated with etidronate were compared with controls. Twenty-five patients treated with etidronate (14 males, 11 females) and 24 controls (15 males, 9 females) were identified from the cohort of patients who underwent transplantation between January 1, 1994, and December 31, 1996. RESULTS: There was no difference in mean age, weight, or cumulative dose of corticosteroids between the treatment and control groups. The baseline BMD measurement was performed at 10.4 +/- 5.3 months after transplantation for treated patients and at 10.7 +/- 4.5 months for controls (P=0.78). Over the subsequent 1-year study period, patients treated with etidronate demonstrated a greater increase in BMD at sites with a preponderance of trabecular bone. Lumbar spine BMD increased 4.3 +/- 6.1% in the treatment group versus 0.55 +/ -5.3% in controls (P<0.03) and trochanter BMD increased 10.3 +/- 11.9% and 2.2 +/- 5.7%, respectively, in the treatment and control groups (P<0.02). CONCLUSIONS: This study establishes the effectiveness of etidronate for treatment of low BMD in renal transplant recipients. Patients selected for treatment had lower baseline BMD than control subjects, yet still showed a clinically important increase in BMD.     

Comparison of the humoral markers of bone turnover and bone mineral density in patients on haemodialysis and continuous ambulatory peritoneal dialysis

Renal osteodystrophy is an important complication in patients with end-stage renal disease on maintenance dialysis. The aim of this study was to compare the biochemical markers of bone formation (serum collagen type I C-terminal propeptide) and resorption (serum deoxypyridinoline - DPD - and pyridinoline - PYR) with the bone mineral density (BMD) at lumbar spine, femoral neck, and forearm in patients with end-stage renal disease on haemodialysis (HD) versus continuous ambulatory peritoneal dialysis (CAPD). Fifty-nine adult patients, 45 on CAPD (18 females, 27 males) and 14 on HD (2 females, 12 males), were studied. The mean age was 44 +/- SEM 1.6 and 54.4 +/- 4.8 years, respectively. No significant differences in serum calcium, phosphorus, creatinine, and parathyroid hormone were found between patients on HD and CAPD in predialysis samples. Serum urea was significantly lower (p = 0.02) in the CAPD group. Serum PYR (nmol/l) and DPD (nmol/l) were significantly higher in patients on HD as compared with those on CAPD: 105 +/- 23.3 versus 43.7 +/- 3.47 (p = 0.007) and 31.0 +/- 2.4 versus 24.4 +/- 1.4 (p = 0.027), respectively. The results were still significantly higher in the HD patients following correction for serum creatinine and body mass index. There was a close correlation between dialysate DPD and creatinine in both dialysis modalities (HD r = 0.9, CAPD r = 0.76). The clearance of DPD did not differ significantly between the CAPD membrane and the HD membrane (p = 0.22). Serum collagen type I C-terminal propeptide was not significantly different between the HD and CAPD patients. The results were unaffected following correction for age and gender. The BMD was measured in 38 (65%) of the patients (HD n = 8, CAPD n = 30) by dual-energy X-ray absorptiometry and expressed as 'Z' scores. This was reduced at all sites in the patients with end-stage renal disease. The BMD was significantly lower at the ultradistal forearm (mostly trabecular bone) in HD patients as compared with CAPD patients (n = 0.02). A similar trend was observed at the lumbar spine, although the results failed to reach significance. In the whole population (n = 38), linear regression analysis revealed a significant negative correlation between BMD at the ultradistal forearm and serum PYR (r = -0.35, p = 0.04) and DPD (r = -0.33, p = 0.049). Combined measurements of BMD and biochemical markers of bone resorption may have potential in the identification of patients at high risk of bone loss who may require further evaluation of bone remodeling by bone histomorphometry.     

胰体尾恶性肿瘤与胰头癌外科治疗效果比较

目的研究胰体尾恶性肿瘤的临床病理特点和外科治疗的效果。方法回顾性分析1980年1月至2003年12月我院收治的106例胰体尾恶性肿瘤患者的临床病理表现和术后生存时间,并与同期451例胰头癌患者进行比较。结果胰体尾恶性肿瘤和胰头癌相比,有以下特点：（1）疼痛多见（0．74：0．41,x^2=37．035,P〈0．01）而黄疸少见（0．04：0．75,x^2=155．509,P〈0．01）;（2）总胆红素水平（F=105．341,P〈0．01）、麸丙酮酸转氨胯（SGPT）（F=89．351,P〈0．01）低而白蛋白水平高（F=26．642,P〈0．01）;（3）CEA阳性率较高（0．40：0．24,x^2=6．148,P=0．046）、CA199阳性率较低（0．57：0．86,x^2=24．132,P〈0．01）;（4）同时性肝脏（0．30：0．17,x^2=9．003,P〈0．01）及总体远处转移率（0．38：0．20,x^2=14．266,P〈0．01）显著高于胰头癌;（5）无转移胰体尾恶性肿瘤和胰头癌切除术后的中位生存期均为15个月,无差异（x^2=0．29,P=0．59）;有转移的胰体尾恶性肿瘤切除术后中位生存期（7个月）和未切除的胰体尾恶性肿瘤（6个月）（x^2=0．22,P=0．64）及未切除的胰头癌（5个月）（x^2=0．91,P=0．34）比较无显著差异。无转移时胰体尾肿瘤切除术后的生存显著优于有转移时切除术后（x^2=21．63,P〈0．01）。结论与胰头癌相比胰体尾恶性肿瘤更容易发生远处转移、特别是肝转移。出现远处转移后的胰体尾切除不能延长生存期。远处转移的防治是改善胰体尾恶性肿瘤预后的关键。     

Gender differences in patients with severe aortic stenosis: impact on preoperative left ventricular geometry and function, as well as early postoperative morbidity and mortality.

OBJECTIVE: In patients with severe aortic stenosis, we studied the impact of gender on preoperative left ventricular geometry and function, as well as on early postoperative mortality and morbidity. METHODS: Prospective Doppler echocardiographic evaluation was performed in 99 female patients and 96 males. RESULTS: The patients had severe aortic stenosis and the mean pressure gradients were similar in females and males. Left ventricular diastolic volume adjusted for body surface area (BSA) was larger in males, 55+/-17.4 ml/m2 versus 43+/-13.1 mL/m2 (mean+/-standard deviation; P = 0.0001). The ejection fraction was similar in females (55+/-14%) and males (55+/-13%), and patients of both sexes had significantly lower stroke volume and cardiac index than healthy controls. The relative wall thickness (wall thickness/diastolic diameter ratio) was higher (P = 0.03) in females (0.47+/-0.10) than in males (0.43+/-0.10) Consequently, the diastolic diameter/wall thickness ratio (a substitute for wall tension) was higher (P = 0.02) in males (4.2+/-0.99) than in females (3.9+/-0.80). Compared with survivors, patients who died within 30 days of the operation (n = 17, 11 females) had a smaller body surface area (1.70+/-0.19 vs. 1.82+/-0.19 m2, P = 0.012), smaller left ventricular outflow tract (20.8+/-0.21 vs. 22.0+/-0.22 mm, P = 0.023), higher incidence of abnormal intraventricular flow velocity (33 vs. 8%, P = 0.018) and increased relative wall thickness (0.52+/-0.17 vs. 0.45+/-0.09 P = 0.039). Gender was of no independent importance for early mortality when age and left ventricular outflow tract diameter were accounted for. CONCLUSIONS: Cardiac adaptation to aortic stenosis seems to be influenced by gender, males presenting larger left ventricular volumes and higher wall tension. The echocardiographic findings of a narrow left ventricular outflow tract, abnormally increased intraventricular velocity and increased relative wall thickness identified patients with increased risk of early postoperative mortality. However gender had no independent impact on early postoperative outcome.