High cognitive dietary restraint is associated with increased cortisol excretion in postmenopausal women

BACKGROUND: Cognitive dietary restraint (perceived ongoing effort to limit dietary intake to manage body weight) is common in women at all life stages. In young women, high dietary restraint has been associated with both increased excretion of cortisol (a stress hormone) and reduced bone mass. Whether this occurs in older women is unknown and is reported here for the first time. METHODS: Postmenopausal women (49-75 years old) with high (n = 41) or low (n = 37) dietary restraint were compared to examine differences in urinary cortisol excretion, body composition assessed by dual-energy x-ray absorptiometry (bone mineral density, % body fat), dietary intake, anthropometrics, current exercise, and perceived stress. RESULTS: Women with high or low dietary restraint did not differ in age, body mass index, waist-to-hip ratio, energy intake, perceived stress, current exercise, or measures of body composition. However, urinary cortisol excretion was higher in the high restraint group (248.2 +/- 61.7 nmol/d vs 204.3 +/- 66.1 nmol/d; p =.01). Multiple regression analysis indicated that restraint group (high or low) independently predicted 7.6% of the variance in cortisol excretion. CONCLUSIONS: Postmenopausal women with high dietary restraint excrete more cortisol than do those with low restraint, suggesting that dietary restraint may be a source of stress. Although this was not associated with negative health effects in this sample, further investigation is warranted.     

Effect of dietary protein supplements on calcium excretion in healthy older men and women

Currently there is no consensus on the impact of dietary protein on calcium and bone metabolism. This study was conducted to examine the effect of increasing protein intake on urinary calcium excretion and to compare circulating levels of IGF-I and biochemical markers of bone turnover in healthy older men and women who consumed either a high or a low protein food supplement for 9 wk. Thirty-two subjects with usual protein intakes of less than 0.85 g/kg.d were randomly assigned to daily high (0.75 g/kg) or low (0.04 g/kg) protein supplement groups. Isocaloric diets were maintained by advising subjects to reduce their intake of carbohydrates. Selected biochemical measurements were made at baseline and on d 35 and either d 49 or 63. Changes in urinary calcium excretion in the two groups did not differ significantly over the course of the study. The high protein group had significantly higher levels of serum IGF-I (P = 0.008) and lower levels of urinary N-telopeptide (P = 0.038) over the period of d 35-49 or 63. We conclude that increasing protein intake from 0.78 to 1.55 g/kg.d with meat supplements in combination with reducing carbohydrate intake did not alter urine calcium excretion, but was associated with higher circulating levels of IGF-I, a bone growth factor, and lowered levels of urinary N-telopeptide, a marker of bone resorption. In contrast to the widely held belief that increased protein intake results in calcium wasting, meat supplements, when exchanged isocalorically for carbohydrates, may have a favorable impact on the skeleton in healthy older men and women.     

Potassium citrate prevents increased urine calcium excretion and bone resorption induced by a high sodium chloride diet

The amount of sodium chloride in the diet of industrialized nations far exceeds physiological requirements. The impact of abundant dietary salt on skeletal health has yet to be established, but is potentially detrimental through increased urinary calcium losses. We examined the effect of increased dietary sodium chloride on urine calcium excretion and bone turnover markers in postmenopausal women and, further, whether potassium citrate attenuates the effects of increased dietary salt. Postmenopausal women (n = 60) were adapted to a low-salt (87 mmol/d sodium) diet for 3 wk, then randomized to a high-salt (225 mmol/d sodium) diet plus potassium citrate (90 mmol/d) or a high-salt diet plus placebo for 4 wk. Urine calcium, urine N-telopeptide, urine cAMP, serum osteocalcin, and fasting serum PTH were measured at the end of the low- and high-salt diets. On the high salt plus placebo diet, urine calcium increased 42 +/- 12 mg/d (mean +/- SEM), but decreased 8 +/- 14 mg/d in the high salt plus potassium citrate group (P = 0.008, potassium citrate vs. placebo, unpaired t test). N-telopeptide increased 6.4 +/- 1.4 nanomoles bone collagen equivalents per millimole creatinine in the high salt plus placebo group and 2.0 +/- 1.7 nanomoles bone collagen equivalents per millimole creatinine in the high salt plus potassium citrate group (P < 0.05, potassium citrate vs. placebo, unpaired t test). Osteocalcin, PTH, and cAMP were not significantly altered. The addition of oral potassium citrate to a high-salt diet prevented the increased excretion of urine calcium and the bone resorption marker caused by a high salt intake. Increased intake of dietary sources of potassium alkaline salts, namely fruit and vegetables, may be beneficial for postmenopausal women at risk for osteoporosis, particularly those consuming a diet generous in sodium chloride.     

Lowering dietary protein to U.S. Recommended dietary allowance levels reduces urinary calcium excretion and bone resorption in young women

High-protein diets increase calciuria. No previous studies have examined the ad libitum U.S. diet's effect on calciuria or bone resorption.Thirty-nine healthy, premenopausal women consuming ad libitum diets [mean, 1.1 g/kg protein, 819 mg (20.5 mmol) Ca, 1152 mg (37 mmol) P, 129 mmol Na] were switched to isocaloric diets containing the U.S. recommended dietary allowance (RDA) of protein (0.8 g/kg) and similar amounts of calcium, phosphorus, and sodium. Bone resorption and related endpoints were assessed before and 1 wk after the switch.As dietary protein changed from ad libitum to RDA levels, mean urine nitrogen decreased 26% (2.4 g/d; P < 0.001) and mean blood urea nitrogen decreased 15% (1.9 mg/dl; P < 0.001). Mean urine pH increased from 6.3 to 6.8 (P < 0.001), and net renal acid excretion (NRAE = urine ammonium plus titratable acids minus bicarbonate) decreased 68% (21.4 mEq/d; P < 0.001). Mean urinary calcium decreased 32% [42 mg (1 mmol)/d; P < 0.001], and bone resorption urine N-telopeptides) decreased 17% (74 micromol bovine collagen equivalents/d; P < 0.001). Mean serum calcium, PTH, and 1,25 dihydroxy vitamin D remained unchanged.In this 2-wk study, decreasing dietary protein from ad libitum to RDA levels decreased NRAE, calciuria and estimates of bone resorption, suggesting that decreased U.S. protein consumption might reduce bone loss. Inasmuch as other dietary modifications, such as increasing vegetable and fruit intake, can result in sustained reductions in NRAE without reducing protein intake, the advisability of reducing protein intake for skeletal protection from acid attack requires further investigation.     

The effect of dietary fruits and vegetables on urinary galactitol excretion in galactose-1-phosphate uridyltransferase deficiency

Summary Even on a lactose-restricted diet, urinary galactitol excretion and erythrocyte galactose-1-phosphate levels are persistently elevated in patients with galactose-1-phosphate uridyltransferase deficiency. In order to determine the contribution of galactose in dietary fruits and vegetables to this phenomenon, (1) the content of galactose in a lactose-free diet was directly measured when a galactosaemic patient's diet was specifically enriched in those fruits and vegetables which contain relatively large amounts of free galactose and (2) galactitol excretion was determined during ingestion of this diet for 3 weeks and while on a synthetic diet for 1 week that provided <8 mg galactose/day. For comparison the effect of a 3-week supplementation of 200 mg galactose/day was determined. The measured intake in total foodstuffs matched the theoretical content of galactose in the patient's diet based on amounts in fruits and vegetables alone, thus supporting the concept that fruits and vegetables are primarily responsible for galactose intake in a lactose-free diet. All of the dietary manipulations, however, had relatively little effect on metabolite levels, suggesting that endogenous galactose production is primarily responsible for the elevated levels of galactose metabolites routinely detected in patients on lactose-restricted diets.     

Individual renin-aldosterone responses of clinically healthy young Japanese men to dietary sodium and posture.

Responses to the changes in dietary sodium and posture were investigated in 9 young clinically healthy Japanese males who customarily consumed a larger amount of salt than North Americans or Europeans of mixed white ethnic background. Plasma renin activity (PRA), plasma aldosterone concentration (PAC), and urinary aldosterone excretion rate (AER) differed at each end of 3- to 4-day spans on a "control", a high-salt and a low-salt diet and of furosemide administration. PRA and PAC, also determined during the upright position following the supine blood sampling, increased after only 1 hour of standing in each condition (p less than 0.05 or more). PRA and PAC were well correlated in all 4 conditions, regardless of the posture (r = 0.806, p less than 0.001). There were also highly significant correlations between the "supine" PRA or PAC and the preceding 24-hour AER (r = 0.869, p less than 0.001) for PRA; r = 0.855, p less than 0.001 for PAC). Correlation coefficients between PRA and PAC in 9 individual subjects ranged from 0.823 to 0.987. The estimates of constant and slope of the regression line between PRA and PAC varied from subject to subject. The renin-aldosterone axis in response to changes in dietary sodium and posture must be individually assessed.     

Short-term effect of orlistat on dietary glycotoxins in healthy women and women with polycystic ovary syndrome

Exogenous advanced glycation endproducts (AGEs, known atherogenic molecules) abundant in everyday precooked, rich in fat, overheated meals can possibly contribute to the increased risk for diabetes and cardiovascular disease in women with polycystic ovary syndrome (PCOS). The aim of the present study was to investigate the effect of a lipase inhibitor on absorbed food glycotoxins in healthy women and those with PCOS. A 2-day protocol was followed. In the first day, a meal rich in AGE was provided, which on the second day was followed by two 120-mg capsules of lipase inhibitor, orlistat. Serum AGE levels were evaluated at baseline (0 hours), and at 3 and 5 hours postmeal during the study. Thirty-six women were studied, 15 controls (mean age, 28.80 +/- 5.47 years; body mass index, 25.85 +/- 6.73 kg/m(2)) and 21 with PCOS (mean age, 25.29 +/- 5.06 years; body mass index, 30.40 +/- 7.51 kg/m(2)) (University Hospital, Athens, Greece, institutional practice). Serum AGE levels, on day 1, were significantly increased both in the control group and in the PCOS group as compared with basal values (control group, 14.1%; PCOS group, 6.0%; P < .001). The corresponding rise was significantly lower on day 2 when the same meal was combined with orlistat (control group, 4.1%; PCOS group, 2.0%; P < .01). A limitation of the study is that it is a nonplacebo, nonrandomized therapeutic trial where each subject is considered as its own control. In conclusion, this study demonstrated the beneficial effect of orlistat on the absorption of food glycotoxins.     

Interannual study of spot urine–evaluated sodium excretion in young Japanese women

The authors investigated interannual differences in the sodium excretion levels of young healthy Japanese women as estimated from spot urine analysis at Nakamura Gakuen University from 1995 to 2015. Participants included 4931 women aged 18 to 20 years who were classified into three time periods according to year of health check: first (1995–2001), second (2002–2007), and third (2008–2015). Estimated daily urinary sodium and potassium excretion levels and the sodium to potassium ratio were 120.6±31.9 mmol, 35.2±8.1 mmol, and 3.5±0.9, respectively. Adjusted for body weight, sodium excretion, and potassium excretion significantly decreased in the second and third period compared with the first period (P<.001). Systolic blood pressure also decreased in the same way between time periods (P<.001). Estimated urinary excretion levels of sodium and potassium in young Japanese women have decreased over the past 20 years independently of body weight.     

Responsiveness to a self-administered diet history questionnaire in a work-site dietary intervention trial for mildly hypercholesterolemic Japanese subjects: correlation between change in dietary habits and serum cholesterol levels.

Modification of lifestyle, especially of diet, is considered important for prevention of cardiovascular disease. Dietary assessment is generally too troublesome to use in a large number of subjects for prevention. We have therefore developed a self-administered diet history questionnaire (DHQ), an easier dietary assessment method than conventional methods, with reasonable validity for use in dietary intervention studies. Responsiveness, i.e., sensitivity to a change in a target variable, is one type of validity required for a dietary assessment method which is used for the evaluation of the effect of dietary interventions. We examined the responsiveness of the DHQ using the data from a 12-week work-site dietary intervention trial including 63(54 men and 9 women) mildly hypercholesterolemic Japanese (age range: 22-59 years, serum cholesterol > or = 200 mg/dl). Dietary habits were assessed by the DHQ before and after the trial. Pearson's correlation coefficients between the change in serum cholesterol and Keys score calculated from the dietary data were 0.33 and 0.32 (p < 0.01) with and without adjustment for possible confounding factors, respectively. Forty-two percent of the total variation of serum cholesterol change was explained by the initial serum cholesterol level, the change in body mass index, and the Keys score. The results suggest that the DHQ showed adequate responsiveness to the serum cholesterol change resulting from dietary intervention.     

Dose-response of sodium excretion and blood pressure change among overweight, nonhypertensive adults in a 3-year dietary intervention study

A cross-sectional dose-response relationship between sodium intake and blood pressure (BP) has been demonstrated, but evidence for a graded longitudinal effect is limited. Evaluation of BP response to sodium reduction was assessed in a 3-year lifestyle dietary intervention trial. BP changes at 18 and 36 months after enrollment were analysed according to concurrent quantitative changes in sodium excretion and by categories of success in sodium reduction among 1157 men and women, ages 30-54 years, with a diastolic BP (DBP) 83-89 mmHg, systolic BP (SBP) <140 mmHg, body weight 110-165% of sex-specific standard weight, and valid baseline urinary sodium excretion. Participants were randomized to a Sodium Reduction intervention (n=581) or Usual Care (n=576). From a 187 mmol/24 h baseline mean sodium excretion, net decreases were 44 mmol/24 h at 18 months and 38 mmol/24 h at 36 months in Sodium Reduction vs Usual Care. Corresponding net decreases in SBP/DBP were 2.0/1.4 mmHg at 18 months, and 1.7/0.9 mmHg at 36 months. Significant dose-response trends in BP change over quintiles of achieved sodium excretion were seen at both 18 (SBP and DBP) and 36 (SBP only) months; effects appeared stronger among those maintaining sodium reduction. Estimated SBP decreases per 100 mmol/24 h reduction in sodium excretion at 18 and 36 months were 2.2 and 1.3 mmHg before and 7.0 and 3.6 mmHg after correction for measurement error, respectively. DBP changes were smaller and nonsignificant at 36 months. In conclusion, incremental decreases in BP with lower sodium excretion were observed in these overweight nonhypertensive individuals.     

Metabolic, psychological, and health correlates of dietary restraint in healthy postmenopausal women

BACKGROUND: Dietary restraint, a term used to describe the intentional control of food intake to prevent weight gain or promote weight loss, is commonly practiced by older adults, but little is known about its effects on physiology and metabolism. METHODS: We therefore compared a wide range of parameters between groups of healthy non-obese postmenopausal women classified psychometrically as unrestrained eaters (body mass index [BMI] 23.8 +/- 0.6 [SEM] kg/m(2), n = 28) or restrained eaters (BMI 24.5 +/- 0.5, n = 39). Measurements were made of reported micronutrient intakes, cardiopulmonary function, hematology, body temperature, skin thickness, bone mass, and immune function; in addition, self-perceived health, mood, and some dimensions of eating behavior were assessed by questionnaire. RESULTS: Macronutrient and micronutrient intakes were not significantly different between restrained and unrestrained eaters reporting energy intake to within 30% of predicted total energy expenditure. Restrained eaters had significantly lower hemoglobin (12.9 +/- 0.1 [SEM] vs 13.2 +/- 0.1 g/dl; p <.05), but values were within the normal range in both groups. In addition, restrained eaters scored significantly higher on the Eating Attitudes Test (p <.01) and drive-for-thinness (p <.001) and maturity fears (p <.05) subscores of the Eating Disorders Inventory, but values were again within the normal range. No other parameter differed significantly between groups. CONCLUSIONS: In this normal-weight population, restrained eating was not associated with detrimental effects in a wide range of physiological, metabolic, and health characteristics. Further work is needed to determine the relevance of these results to the general population.     

Lymphocyte count was significantly associated with hyper-LDL cholesterolemia independently of high-sensitivity C-reactive protein in apparently healthy Japanese

The aim of this study was to investigate the association between leukocyte subtype counts and hyper-LDL cholesterolemia, hypertriglyceridemia, and hypo-HDL cholesterolemia. Logistic regressions using hyper-LDL cholesterolemia, hypertriglyceridemia, and hypo-HDL cholesterolemia as a dependent variable and total leukocyte, basophil, eosinophil, neutrophil, lymphocyte, and monocyte counts as an independent variable were calculated adjusting for age, body mass index (BMI), high-sensitivity C-reactive protein (hs-CRP), smoking, drinking, and physical activity in apparently healthy Japanese men (1,803) and women (1,150). The odds ratio (OR) of hyper-LDL cholesterolemia for total leukocyte, eosinophil, and lymphocyte counts, the OR of hypertriglyceridemia for total leukocyte, eosinophil, neutrophil, and lymphocyte counts, and the OR of hypo-HDL cholesterolemia for total leukocyte, neutrophil, and lymphocyte counts were significant in men, and the OR of hyper-LDL cholesterolemia, for lymphocyte count, and the OR of hypo-HDL cholesterolemia for eosinophil count were significant in women. Lymphocyte count was significantly associated with hyper-LDL cholesterolemia independently of hs-CRP in apparently healthy Japanese.     

Metabolism of dietary sulphate: absorption and excretion in humans.

Dietary sulphate may affect colonic pathophysiology because sulphate availability determines in part the activity of sulphate reducing bacteria in the bowel. The main product of sulphate reducing bacterial oxidative metabolism, hydrogen sulphide, is potentially toxic. Although it is generally believed that the sulphate ion is poorly absorbed, there are no available data on how much sulphate reaches the colon nor on the relative contributions from diet and endogenous sources. To resolve these questions, balance studies were performed on six healthy ileostomists and three normal subjects chosen because they did not have detectable sulphate reducing bacteria in their faeces. The subjects were fed diets which varied in sulphate content from 1.6-16.6 mmol/day. Sulphate was measured in diets, faeces (ileal effluent in ileostomists), and urine by anion exchange chromatography with conductivity detection. Overall there was net absorption of dietary sulphate, with the absorptive capacity of the gastrointestinal tract plateauing at 5 mmol/day in the ileostomists and exceeding 16 mmol/day in the normal subjects. Endogenous secretion of sulphate in the upper gastrointestinal tract was from 0.96-2.6 mmol/day. The dietary contribution to the colonic sulphate pool ranged up to 9 mmol/day, there being linear identity between diet and upper gastrointestinal losses for intakes above 7 mmol/day. Faecal losses of sulphate were trivial (less than 0.5 mmol/day) in the normal subjects at all doses. It is concluded that diet and intestinal absorption are the principal factors affecting the amounts of sulphate reaching the colon. Endogenous secretion of sulphate by colonic mucosa may also be important in determining amounts of sulphate in the colon.     

Urinary nitrate excretion is increased in patients with rheumatoid arthritis and reduced by prednisolone.

OBJECTIVES--To determine daily production of nitric oxide (NO) measured as urinary nitrate excretion, and the effect of prednisolone in patients with rheumatoid arthritis (RA). METHODS--Twenty four hour urinary nitrate was measured by gas chromatography in 10 patients with RA, before and two to four weeks after commencement of prednisolone 0.5 mg/kg body weight, and in 18 healthy controls. RESULTS--Before the start of prednisolone treatment the urinary nitrate excretion in patients with RA was 2.7-fold greater (p < 0.001) than that in healthy volunteers. After prednisolone it decreased significantly, by 28%, at which time inflammatory activity (as indicated by C reactive protein, erythrocyte sedimentation rate, joint count, and early morning stiffness) was also reduced considerably. Despite this decrease, the urinary nitrate excretion in patients with RA remained twice that in the control group (p < 0.05). CONCLUSIONS--Our data suggest that the endogenous production of NO is enhanced in patients with RA. Furthermore, the results indicate that, in parallel with suppression of inflammation, this increased NO synthesis could be reduced by prednisolone treatment.     

The impact of restricted gestational weight gain by dietary intervention on fetal growth in women with gestational diabetes mellitus

Aims/hypothesis

We aimed to investigate the impact of maternal gestational weight gain (GWG) during dietary treatment on fetal growth in pregnancies complicated by gestational diabetes (GDM).

Methods

This was a retrospective cohort study of 382 women consecutively diagnosed with GDM before 34 weeks’ gestation with live singleton births in our centre (Center for Pregnant Women with Diabetes, Rigshospitalet, Copenhagen, Denmark) between 2011 and 2017. The women were stratified into three groups according to restricted (53%), appropriate (16%) and excessive (31%) weekly GWG during dietary treatment (using the Institute of Medicine guidelines) to estimate compliance with an energy-restricted ‘diabetes diet’ (6000 kJ/day [1434 kcal/day], with approximately 50% of energy intake coming from carbohydrates with a low glycaemic index, and a carbohydrate intake of 175 g/day). Insulin therapy was initiated if necessary, according to local clinical guidelines.

Results

Glucose tolerance, HbA_1c, weekly GWG before dietary treatment (difference between weight at GDM diagnosis and pre-pregnancy weight, divided by the number of weeks) and SD score for fetal abdominal circumference were comparable across the three groups at diagnosis of GDM at 27⁶?±?5¹ weeks (gestation time is given as weeks^days). The women were followed for 10⁰?±?5¹ weeks, during which 54% received supplementary insulin therapy and the average (mean) GWG during dietary treatment was 0 kg, 3 kg and 5 kg in the three groups, respectively. Excessive weekly GWG during dietary treatment, reflecting poor dietary adherence was associated with increasing HbA_1c (p?=?0.014) from diagnosis of GDM to late pregnancy and infants with a birthweight-SD score of 0.59?±?1.6. In contrast, restricted weekly GWG during dietary treatment, reflecting strict dietary adherence, was associated with decreasing HbA_1c (p?=?0.001) from diagnosis of GDM to late pregnancy and infants with a birthweight-SD score of 0.15?±?1.1, without increased prevalence of infants born small for gestational age. Excessive GWG during dietary treatment and late-pregnancy HbA_1c were identified as potentially modifiable clinical predictors of infant birthweight-SD score (p?=?0.02 for both variables) after correction for confounders.

Conclusions/interpretation

Restricted GWG during dietary treatment was associated with healthier fetal growth in women with GDM. GWG during dietary treatment and late-pregnancy HbA_1c were identified as potentially modifiable clinical predictors of infant birthweight-SD score.