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Context: More data are needed on the potential benefits and risks of gestational weight gain (GWG) less than recommended and excessive GWG in women with gestational diabetes (GDM) compared to women with normal glucose tolerance (NGT) during pregnancy., Objective: This work aimed to evaluate association of gestational weight gain (GWG) as low, within, or above (excessive) according to Institute of Medicine (IOM) guidelines, with pregnancy outcomes in women with gestational diabetes (GDM) and normal glucose tolerance (NGT)., Methods: This prospective cohort study included 7 Belgian hospitals and 1843 women receiving universal GDM screening with a 75-g oral glucose tolerance test. Pregnancy outcomes and postpartum characteristics were the main outcome measures., Results: Women with GDM and low GWG (n = 97, 52.4%) had similar rates of small-for-gestational age infants and preterm delivery, were less often overweight or obese postpartum (35.7% [30] vs 56.5% [26]; P < .022) and less often had postpartum weight retention (PPWR) (48.8% [41] vs 87.9% [40]; P < .001) compared to GWG within range (n = 58, 31.3%). GDM with excessive GWG (n = 30, 16.2%) more often had neonatal hypoglycemia (30.8% (8) vs 5.9% [3], aOR 7.15; 95% CI, 1.52-33.63; P = .013) compared to GWG within range. NGT with excessive GWG (28.3% [383]) more often had instrumental delivery (15.9% [61] vs 11.9% [64], aOR 1.53; 95% CI, 1.03-2.27; P = .035) and more large-for-gestational age infants (19.3% [74] vs 10.4% [56], aOR 1.67; 95% CI, 1.13-2.47; P = .012) compared to GWG within range., Conclusion: GWG below IOM guidelines occurred frequently in GDM women, without increased risk for adverse pregnancy outcomes and with better metabolic profile postpartum. Excessive GWG was associated with increased risk for neonatal hypoglycemia and worse metabolic profile postpartum in women with GDM, and with higher rates of LGA and instrumental delivery in NGT women., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims: To determine the impact of depressive symptoms on pregnancy outcomes and postpartum quality of life in women with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGT)., Methods: 1843 women from a prospective cohort study received universal GDM screening with an oral glucose tolerance test (OGTT). The Center for Epidemiologic Studies-Depression questionnaire was completed before GDM diagnosis was communicated and in GDM women in early postpartum. All participants completed the 36-Item Short Form Health Survey (SF-36) health survey postpartum., Results: Women who developed GDM (231; 12.5%) had significantly more often depressive symptoms than NGT (1612; 87.5%) women [21.3% (48) vs 15.1% (239), odds ratio (OR) 1.52, 95% confidence interval (CI) (1.08-2.16), P = 0.017]. Compared to GDM women without depressive symptoms, depressed GDM women attended less often the postpartum OGTT [68.7% (33) vs 87.6% (155), P = 0.002], remained more often depressed [37.1% (13) vs 12.4% (19), P < 0.001], and had lower SF-36 scores postpartum. There were no significant differences in pregnancy outcomes between both groups. Rates of labor inductions were significantly higher in the NGT group with depressive symptoms compared to the nondepressed NGT group [31.7% (75) vs 24.7% (330), adjusted OR (aOR) 1.40, 95% CI (1.01-1.93), P = 0.041]. NGT women with depressive symptoms had lower SF-36 scores (P < 0.001) postpartum compared to nondepressed NGT women., Conclusions: Women with antenatal symptoms of depression develop more often GDM. GDM women with depressive symptoms remain more often depressed postpartum with lower quality of life. NGT women with depressive symptoms have higher rates of labor inductions and lower quality of life postpartum compared to nondepressed NGT women., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims: To determine impact of mild fasting hyperglycemia in early pregnancy (fasting plasma glucose [FPG] 5.1-5.5 mmol/L) on pregnancy outcomes., Methods: We measured FPG at 11.9 ± 1.8 weeks in 2006 women from a prospective cohort study. Women with FPG ≥5.6 mmol/L (19) received treatment and were excluded from further analyses. A total of 1838 women with FPG <5.6 mmol/L received a 75 g oral glucose tolerance test (OGTT) between 24 and 28 weeks of pregnancy., Results: Of all participants, 78 (4.2%) had FPG 5.1 to 5.5 mmol/L in early pregnancy, of which 49 had a normal OGTT later in pregnancy (high fasting normal glucose tolerance [NGT] group). Compared with the NGT group with FPG <5.1 mmol/L in early pregnancy (low fasting NGT group, n = 1560), the high fasting NGT group had a higher body mass index (BMI), higher insulin resistance with more impaired insulin secretion and higher FPG and 30 minute glucose levels on the OGTT. The admission rate to neonatal intensive care unit (NICU) was significantly higher in the high fasting NGT group than in the low fasting NGT group (20.4% [10] vs 9.3% [143], P = .009), with no difference in duration (7.0 ± 8.6 vs 8.4 ± 14.3 days, P = .849) or indication for NICU admission between both groups. The admission rate to NICU remained significantly higher (odds ratio 2.47; 95% confidence interval 1.18-5.19, P = .017) after adjustment for age, BMI, and glucose levels at the OGTT., Conclusions: When provision of an OGTT is limited such as in the Covid-19 pandemic, using FPG in early pregnancy could be an easy alternative to determine who is at increased risk for adverse pregnancy outcomes., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: Since many European countries use risk factor screening for gestational diabetes mellitus (GDM), we aimed to determine the performance of selective screening for GDM based on the 2013 WHO criteria., Design and Methods: Overall, 1811 women received universal screening with a 75 g oral glucose tolerance test (OGTT) with GDM in 12.5% (n = 231) women based on the 2013 WHO criteria. We retrospectively applied different European selective screening guidelines to this cohort and evaluated the performance of different clinical risk factors to screen for GDM., Results: By retrospectively applying the English, Irish, French and Dutch guidelines for selective screening, respectively 28.5% (n = 526), 49.7% (n = 916), 48.5% (n = 894) and 50.7% (n = 935) had at least one risk factor, with GDM prevalence of respectively 6.5% (n = 120), 7.9% (n = 146), 8.0% (n = 147) and 8.4% (n = 154). Using maternal age ≥30 and/or BMI ≥25 for screening, positive rate was 69.9% (n = 1288), GDM prevalence 10.2% (n = 188), sensitivity 81.4% (CI: 75.8–86.2%) and specificity 31.8% (CI: 29.5–34.1%). Adding other clinical risk factors did not improve detection. GDM women without risk factors had more neonatal hypoglycemia (14.4 vs 4.0%, P = 0.001) and labor inductions (39.7 vs 25.9%, P = 0.020) than normal-glucose tolerant women, and less cesarean sections than GDM women with risk factors (13.8 vs 31.0%, P = 0.010)., Conclusions: By applying selective screening by European guidelines, about 50% of women would need an OGTT with the lowest number of missed cases (33%) by the Dutch guidelines. Screening with age ≥30 years and/or BMI ≥25, reduced the number of missed cases to 18.6% but 70% would need an OGTT., (© 2019 European Society of Endocrinology)

Background: Mastectomy with immediate breast reconstruction (IBR) is a surgical strategy in breast cancer when breast-conserving surgery is not an option. There is a lack of evidence showing an advantage of mastectomy plus IBR over mastectomy alone on health-related quality of life (QoL)., Methods: A large prospective multicentre survey, STIC-RMI (support of innovative and expensive techniques - immediate breast reconstruction), was undertaken to study the changes in QoL in patients treated by mastectomy with or without IBR. Patients were recruited between 2007 and 2009. European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23 instruments were used to assess QoL before operation, and at 6 and 12 months after surgery. A propensity score was used to compare QoL between mastectomy alone and mastectomy plus IBR, with limited bias., Results: A total of 595 patients were included from 22 French academic hospitals, of whom 407 (68·4 per cent) underwent IBR. One-year data were available for 71·1 per cent of patients. Factors associated with IBR were age, histological tumour type, palpable nodes and an attempt at breast-conserving surgery. At inclusion, QoL was significantly better in the IBR group (P < 0·001) and there was no significant change in either group during 1 year compared with baseline. Results for the QLQ-BR23 functional dimension varied according to propensity score quartiles; IBR had no influence in the lowest quartile. In the upper quartiles, QoL increased slightly over the year among patients who had IBR, whereas it decreased among those who had mastectomy alone (P = 0·037). Satisfaction with the cosmetic outcome strongly influenced QoL, especially in upper quartiles (P < 0·001). However, an unsatisfactory outcome after IBR was still considered a better condition than simple mastectomy., Conclusion: The QoL benefit provided by IBR depends on patients' life status at inclusion; young active women with an in situ tumour are more likely to preserve their QoL after IBR., (© 2017 BJS Society Ltd Published by John Wiley & Sons Ltd.)

Introduction: While there is increasing interest in studying aspects of communication processes in sex research, the association between dyadic sexual communication and relationship and sexuality outcomes has not yet been examined in pre-menopausal women with dyspareunia., Aim: To examine the associations between dyadic sexual communication and pain, sexual distress, sexual function and dyadic adjustment in women with self-reported dyspareunia and their male partners., Methods: Pre-menopausal women (n=38; M age=24.92, SD=6.12) with self-reported dyspareunia from a community sample and their partners (n=38; M age=26.71, SD=6.59) completed an online survey. The Actor-Partner Interdependence Model was used in order to investigate both actor and partner effects., Main Outcome Measures: Both members of the couple completed: (i) the Dyadic Sexual Communication Scale and (ii) the Dyadic Adjustment Scale; women also completed (iii) the Female Sexual Function Index, (iv) the Female Sexual Distress Scale, and (v) a Visual Analogue Scale on pain during intercourse; and men also completed (vi) the International Index of Erectile Functioning., Results: Controlling for relationship duration, women's better dyadic sexual communication was significantly associated with their higher levels of sexual function (P=0.028), lower levels of sexual distress (P=0.003) and higher levels of dyadic adjustment (P=0.005), but not with their pain or men's sexual function or dyadic adjustment. Controlling for relationship duration, men's better dyadic sexual communication was associated with their higher levels of dyadic adjustment (P=0.027) but not with their sexual function, nor with women's sexual function or dyadic adjustment., Conclusions: These findings contribute to the theoretical knowledge on interaction processes in couples with dyspareunia and suggest that it may be important to enhance open and direct communication about sexual matters in couples with dyspareunia., (© 2014 International Society for Sexual Medicine.)

Introduction: Endometrial cancer (EC) can affect sexual functioning based on anatomical, physiological, psychological, and relational mechanisms., Aim: The aim of this study was to prospectively investigate sexual adjustment of women with EC during a follow-up period of 2 years after surgical treatment and to compare the results with women who underwent a hysterectomy for a benign gynecological condition and healthy control women., Methods/main Outcome Measures: In this prospective controlled study, participants completed the Short Sexual Functioning Scale, Specific Sexual Problems Questionnaire, Beck Depression Inventory Scale, World Health Organization-5 Well-being Scale, and Dyadic Adjustment Scale to assess various aspects of sexual and psychosocial functioning before undergoing a hysterectomy and 6 months, 1 year, and 2 years after surgery., Results: Eighty-four women with EC, 84 women with a benign gynecological condition, and 84 healthy controls completed the survey. In EC survivors, no differences were found in sexual functioning during prospective analyses. In comparison with women with a benign gynecological condition, significantly more EC patients reported entry dyspareunia 1 year after surgical treatment. Moreover, compared with healthy women, pre- and postoperatively, significantly more EC patients reported sexual dysfunctions, including sexual desire dysfunction, arousal dysfunction, entry dyspareunia, and a reduced intensity of orgasm. Furthermore, compared with healthy controls, EC patients reported significantly lower overall well-being 1 year after surgical treatment. Nevertheless, consensus in the partner relationship was significantly higher in EC patients compared with healthy controls. Moreover, before treatment, quality of partner relationship was negatively associated with sexual arousal dysfunction and orgasm dysfunction., Conclusions: In EC patients, no differences were found in sexual functioning when prospectively comparing the situation before surgery with the situation after surgery. However, when compared with healthy controls, EC patients are at high risk for sexual dysfunctions, both before and after surgical treatment., (© 2014 International Society for Sexual Medicine.)

Introduction: Although research that takes into account partner and relationship factors in dyspareunia is slowly emerging, little is known about how these couples communicate about their sexuality. Additionally, partner psychosexual adjustment has not been examined in a controlled fashion., Aim: This study aimed to compare dyadic sexual communication, dyadic adjustment, psychological adjustment, and sexual well-being of women with self-reported dyspareunia and their partners with those of pain-free control women and their partners., Methods: Premenopausal women (n = 38; mean [M] age = 24.92) with self-reported dyspareunia, their partners (n = 38; M age = 26.71), as well as pain-free control women (n = 44; M age = 25.86) and their partners (n = 44; M age = 27.95) completed an online survey measuring dyadic sexual communication, dyadic adjustment, anxiety, depression, sexual functioning, and sexual distress., Main Outcome Measures: Assessments of women and men's (i) dyadic sexual communication; (ii) dyadic adjustment; (iii) anxiety; (iv) depression; (v) sexual functioning; and (vi) women's sexual distress were the main outcome measures., Results: Compared with pain-free controls, women with dyspareunia reported significantly poorer dyadic sexual communication, a difference not found between partners of women with dyspareunia and control partners. Compared with partners of control women, those of women with dyspareunia reported significantly more impaired sexual functioning. No differences in dyadic adjustment were found between women with dyspareunia and pain-free control women, or between their respective partners. Finally, compared with control women, those with dyspareunia reported significantly more impaired psychological and sexual well-being., Conclusions: Findings suggest that dyspareunia impacts not only the psychosexual adjustment of affected women but also that of their partners. It seems relevant to include both members of the couple in future research and treatment for dyspareunia., (© 2014 International Society for Sexual Medicine.)

Introduction: Although it is known that women with dyspareunia suffer from impaired psychological and sexual functioning, the study of the various dimensions of sexual self-schema and their associations with these outcomes has been neglected., Aim: To examine whether self-image cognitions about vaginal penetration, body image, and feelings and beliefs about one's own genitals contribute to the variance in pain, sexual functioning, and sexual distress., Methods: Premenopausal women (n = 231; M age = 24.85, SD = 5.55) with self-reported dyspareunia completed an online survey focusing on self-image cognitions about vaginal penetration, body image, female genital self-image, pain during intercourse, sexual functioning, sexual distress, anxiety, and catastrophizing., Main Outcome Measures: (i) Pain intensity during intercourse, (ii) the Female Sexual Function Index without the Pain subscale, and (iii) the Female Sexual Distress Scale., Results: Controlling for anxiety and catastrophizing, negative self-image cognitions about vaginal penetration, negative body image, and negative genital self-image together accounted for a portion of the variance in increased pain intensity, sexual dysfunction, and sexual distress. However, only self-image cognitions about vaginal penetration (β = 0.25, P = 0.005) contributed uniquely to the variance in pain intensity, whereas self-image cognitions about vaginal penetration (β = -0.18, P = 0.048) and genital self-image (β = 0.21, P = 0.008) contributed independently to the variance in sexual functioning. Finally, self-image cognitions about vaginal penetration (β = 0.28, P < 0.001), body image (β = 0.24, P < 0.001) and genital self-image (β = -0.14, P = 0.006) each contributed independently to the variance in sexual distress., Conclusions: Findings suggest that self-image cognitions about vaginal penetration and feelings and beliefs about one's own body and genitals are associated with pain and sexuality outcomes in women with dyspareunia., (© 2013 International Society for Sexual Medicine.)

Introduction: Vulvectomy is an intrusive treatment option for women with vulvar malignancy that theoretically may affect sexual function., Aim: This study aims to provide a comprehensive review of the literature on the impact of surgical treatment for vulvar malignancy on sexual functioning, overall quality of life, and partner relationship., Methods: Systematic search of the medical literature on PubMed, PsycINFO, Cochrane database, Google Scholar and Embase using a number of related terms including vulvar malignancy, vulvar cancer, vulva cancer, vulval cancer, vulvectomy, sexual function, partner relation, quality of life, and psychological functioning., Main Outcome Measure: Measures and indicators of sexual function, overall quality of life, and partner relationship following vulvectomy for vulvar malignancy., Results: There is evidence that women who undergo surgical treatment for vulvar cancer or vulvar intraepithelial neoplasia are at high risk for sexual dysfunctions, dissatisfaction with partner relationship, and psychological difficulties. Factors associated with posttreatment sexual dysfunction include patient's increased age, poor overall well-being, history of depression, anxiety, and excision size of vulvar malignancy., Conclusions: Surgical treatment of vulvar cancer has a negative impact on sexual function, quality of life, and satisfaction with partner relationship. However, hitherto only little research effort has been directed to postoperative sexual well-being in vulvar cancer survivors. There is a need for more methodological sound prospective studies that explore sexual function, quality of life, and partner relationship and its predictors over time in vulvar cancer patients., (© 2011 International Society for Sexual Medicine.)

Pregnancy-induced metabolic changes are regulated by signals from an expanded adipose organ. Placental growth factor (PlGF), acting through vascular endothelial growth factor receptor-1, may be among those signals. There is a steep rise in circulating PlGF during normal pregnancy, which is repressed in gravidas who develop preeclampsia. PlGF-deficiency in mice impairs adipose vascularization and development. Here we studied young-adult PlGF-deficient (PlGF(-/-)) and wild-type mice on a high-fat diet in the nongravid state and at embryonic day (E) 13.5 or E18.5 of gestation. Litter size and weight were normal, but E18.5 placentas were smaller in PlGF(-/-) pregnancies. PlGF(-/-) mice showed altered intraadipose dynamics, with the following: 1) less blood vessels and fewer brown, uncoupling protein (UCP)-1-positive, adipocytes in white sc and perigonadal fat compartments and 2) white adipocyte hypertrophy. The mRNA expression of beta(3)-adrenergic receptors, peroxisome proliferator-activated receptor-gamma coactivator-1alpha, and UCP-1 was decreased accordingly. Moreover, PlGF(-/-) mice showed hyperinsulinemia. Pregnancy-associated changes were largely comparable in PlGF(-/-) and wild-type dams. They included expanded sc fat compartments and adipocyte hypertrophy, whereas adipose expression of key angiogenesis/adipogenesis (vascular endothelial growth factor receptor-1, peroxisome proliferator-activated receptor-gamma(2)) and thermogenesis (beta(3)-adrenergic receptors, peroxisome proliferator-activated receptor-gamma coactivator-1alpha, and UCP-1) genes was down-regulated; circulating insulin levels gradually increased during pregnancy. In conclusion, reduced adipose vascularization in PlGF(-/-) mice impairs adaptive thermogenesis in favor of energy storage, thereby promoting insulin resistance and hyperinsulinemia. Pregnancy adds to these changes by PlGF-independent mechanisms. Disturbed intraadipose dynamics is a novel mechanism to explain metabolic changes in late pregnancy in general and preeclamptic pregnancy in particular.

Low birth weight has long-term effects on glucose-insulin homeostasis. Factors that could mediate intra-uterine "programing" of glucose homeostasis include endogenous and exogenous glucocorticoids, adipose tissue-secreted factors such as adiponectin, and in utero hypoxia. Here, we studied 123 fetuses with gestational age (GA) between 25 and 37 wk and birth weight sd score (BW SDS) between -2.79 and 2.42. We measured proinsulin, C-peptide, insulin, and adiponectin in umbilical vein (UV) plasma and calculated the proinsulin to insulin ratio as a measure of beta-cell secretory function. These indices were related to GA, BW SDS, time since the last maternal betamethasone administration, and blood gas data. Insulin and C-peptide were correlated with BW SDS but not GA, whereas the proinsulin to insulin ratio was inversely correlated with BW SDS. The proinsulin to insulin ratio was raised (P = 0.002) in fetuses with UV PO(2) less than or equal to 21.3 mm Hg (i.e. the 50th percentile) compared with those with PO(2) more than 21.3 mm Hg, inferring that in utero hypoxia engenders beta-cell secretory dysfunction. Proinsulin, insulin, and C-peptide were markedly but transiently (<24 h) elevated after maternal betamethasone administration, returning thereafter to concentrations measured in noncorticosteroid-treated fetuses. However, there was considerable variability within the less than 24-h betamethasone group: the indices of insulin secretion were related to UV PO(2), suggesting that hypoxia attenuates the responsiveness of fetal beta-cells to corticosteroids. Adiponectin was not related to any of the insulin indices. In conclusion, we have identified two environmental signals that modulate fetal insulin output: maternal corticosteroids produce a transient surge in fetal insulin synthesis and secretion, whereas in utero hypoxia disturbs the insulin secretory process.

The prediction of birth weight may be improved by the measurement of hormones or growth factors in the mother. We measured body weight (BW) and plasma levels of placental GH (PGH), IGF-I, IGF-binding protein-1 (IGFBP-1), and leptin at the time of the glucose challenge test (GCT) in 289 women, who were pregnant with a single fetus, between 24 and 29 wk gestational age (GA). Delivery occurred 12 +/- 2 (mean +/- SD) wk later. First, we examined which variables regulate these hormonal factors. Multiple regression showed that PGH concentrations were determined by GA at sampling and were negatively related to BW. IGF-I levels were mainly determined by PGH, and also by insulin, BW, and (negatively) age. IGFBP-1 concentrations were negatively determined by BW, insulin, and IGF-I. BW was also a powerful determinant of leptin levels, with insulin as a less robust determinant. Second, we examined the relation to glucose levels. PGH, IGF-I, and IGFBP-1 concentrations were not correlated with post-GCT glucose levels and were comparable in women with a normal or disturbed GCT (glucose >/=7.8 mmol/liter; n = 72). Finally, we examined the relation with birth weight and placental weight. Birth weight, corrected for GA and stratified into percentile groups, and the ponderal index at birth were strongly related to maternal BW, but not to maternal PGH, IGF-I, or IGFBP-1 levels. Neither was maternal leptin related to birth weight, but leptin concentrations were slightly higher in women who delivered obese babies. Placental weight was not related to any of the hormonal factors. This prospective study indicates that the variation in circulating PGH, IGF-I, IGFBP-1, and leptin between 24 and 29 wk of pregnancy is strongly dependent on maternal BW, but is unrelated to glucose tolerance. In addition, the measurement of PGH, IGF-I, IGFBP-1, or leptin at the time of the GCT is not useful clinically to predict birth weight.

Vitamin D and bone mineral metabolism during pregnancy were studied in 17 diabetic and 13 control BB rats. On day 21 of pregnancy, reduced mean levels of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3; 56.9 vs. 97.9 pg/ml; P less than 0.0001] and vitamin D-binding protein (304 vs. 482 micrograms/ml; P less than 0.0001) were found in the diabetic rats, while the free 1,25-(OH)2D3 concentration was not different from the control level. Total plasma calcium and total plasma protein concentrations were also significantly decreased in the diabetic group, but the calculated diffusible calcium was not significantly lower. Calcium and phosphorus urinary excretion were increased in the diabetic rats. There was no difference in bone mineral content. The fetuses of the diabetic BB rat had a lower body weight and were hypoinsulinemic. Both 1,25-(OH)2D3 (41.3 vs. 54.7 pg/ml; P less than 0.01) and vitamin D-binding protein (80 vs. 123 micrograms/ml; P less than 0.001) were decreased in the fetuses of diabetic rats, but the free 1,25-(OH)2D3 concentration was slightly but significantly (6.96 vs. 5.54; P less than 0.05) increased. We observed that the fetuses of diabetic rats had fewer ossification centers, counted with the Alizarin Red S staining method. The fetal ash weight was lower in the diabetic group (16.7 vs. 26.9 mg; P less than 0.0001). In addition, the relative calcium and phosphorus, but not magnesium, content of ash was lower in the fetuses of diabetic rats. This reduced mineral content in fetuses of diabetic mothers could be implicated in the pathogenesis of early neonatal hypocalcemia in infants of diabetic mothers.

Calcium homeostasis was investigated in male BB rats with a diabetes duration of 3-4 weeks and compared with that in nondiabetic littermates either fed ad libitum or receiving selective semistarvation or an oral Ca supplement to obtain additional weight-matched and Ca intake-matched control groups. Diabetic rats had markedly increased food and Ca intake, so that their net Ca balance remained positive despite a 13-fold increase in urinary Ca excretion and a disappearance of active duodenal Ca absorption. Decreased duodenal Ca uptake correlated with decreased 1,25-(OH)2D3 levels (89 +/- 15 vs. 160 +/- 13 pg/ml in nondiabetic rats), decreased duodenal 9K Ca-binding protein concentrations (10 +/- 1 vs. 21 +/- 2 micrograms/mg protein), and decreased number of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]-binding sites in duodenum, although the binding affinity was above normal. Nondiabetic Ca-supplemented rats exhibited a similar response: decreased 1,25-(OH)2D3 (95 +/- 8 pg/ml) and 9K Ca-binding protein (7 +/- 0.5 micrograms/mg protein) concentrations, decreased active duodenal Ca uptake, increased urinary Ca excretion, and a normal net Ca balance. Plasma vitamin D-binding protein levels were decreased by 62% in diabetic rats, due to a marked decrease in production rate, while the plasma half-time remained normal. The free 1,25-(OH)2D3 index was highest in diabetic rats, suggesting partial vitamin D resistance at the duodenal level. In semistarved rats, 1,25-(OH)2D3 levels and active Ca uptake remained normal, and the free 1,25-(OH)2D3 index was increased, together with suppressed vitamin D-binding protein levels. These studies indicate that nutritional abnormalities may contribute to but cannot totally explain the disturbances in vitamin D metabolism, transport, or action at the intestinal level.

Bone morphology and function were studied in male spontaneously diabetic BB rats after 3-4 weeks of diabetes. The tibia and lumbar vertebrae weights were decreased, but the bone calcium percentage remained normal. Bone volumes in the tibial metaphysis and the first lumbar vertebra were normal on quantitative histomorphometry. Osteoclast, osteoblast, and osteoid surface percentages, however, and the calculated daily mineral apposition rate in the tibia (1.0 +/- 0.4 vs. 5.6 +/- 0.6 microns/day) and vertebra (0.2 +/- 0.1 vs. 2.3 +/- 0.2 microns/day) were all severely decreased in diabetic rats. Plasma osteocalcin concentrations were also markedly decreased in diabetic rats (24 +/- 2 vs. 108 +/- 10 ng/ml); the half-times of [125I]osteocalcin were similar in diabetic and nondiabetic rats, indicating that decreased plasma osteocalcin was due to decreased synthesis. Plasma osteocalcin levels were more decreased than expected from their suppressed 1,25-dihydroxyvitamin D3 levels, and 1,25-dihydroxyvitamin D3 injections did not increase plasma osteocalcin in diabetic rats as they did in nondiabetic rats. Bone osteocalcin content was normal in diabetic rats. Photon absorptiometry of tibiae showed a similar bone mineral content in diabetic and nondiabetic rats. Biomechanical properties of diabetic rat femora were all in the normal range. Nondiabetic semistarved rats with the same body weight as diabetic rats exhibited a similar delay in bone growth as diabetic rats, but the osteoblast and osteoid surfaces were normal, and the mineral apposition rate was normal (tibia) or slightly decreased (vertebra). Plasma osteocalcin concentrations were also normal in semistarved rats. Thus, the number and/or function of osteoblasts are severely suppressed in diabetes, and this results in decreased osteoid surface, mineral apposition rate, and plasma osteocalcin levels; moreover, these changes cannot be explained by simple weight loss.