Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Acetates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed2005

Controlling hydrothermal reaction pathways to improve acetic acid production from carbohydrate biomass.

A two-step hydrothermal process to improve the production of acetic acid was discussed. The first step was to accelerate the formation of 5-hydroxymethyl-2-furaldehyde (HMF), 2-furaldehyde (2-FA), and lactic acid (LA), and the second step was to further convert the furans (HMF, 2-FA) and LA produced in the first step to acetic acid by oxidation with newly supplied oxygen. The acetic acid obtained by the two-step process had not only a high yield but also better purity. The contribution of two pathways via furans and LA in the two-step process to convert carbohydrates into acetic acid was roughly estimated as 85-90%, and the ratio of the contributions of furans and LA to yield acetic acid was estimated as 2:1. The fact that WO of carbohydrates is not capable of producing a large amount of acetic acid, while the two-step process can enhance the acetic acid yield, can be explained because formic acid is a basic product of direct oxidation of carbohydrate, and acetic acid in WO of carbohydrates may come from the oxidation of dehydration products of aldose.

Acetic Acid↗
PubMed1979

Acetate transfer across membranes of artificial kidneys in vitro.

To determine the rate of acetate transfer across hemodialysis membranes and to investigate the factors which influence acetate dialysance, we performed experiments with Dow-4, Gambro-13.5, and Travenol UF-II artificial kidneys using 14C-acetate. The rate of acetate dialysance was influenced strongly by the rate of fluid flow through the blood path, similar to the dialysance of other low-molecular-weight solutes. The ultrafiltration of fluid from the blood path to dialysate reduced the rate of transfer of acetate from dialysate to blood. The dialysance of acetate was significantly less than that of urea, despite their nearly identical molecular weights. This was not due to the direction of solute transfer. Experiments with a Kaufman-Leonard dialyzer demonstrated that the permeability of Cuprophane membranes to urea was greater than that to acetate was; this may be due to the charged nature of acetate.

Acetates↗
PubMed1981

Acid-base changes and acetate metabolism during routine and high-efficiency hemodialysis in children.

Changes in acid-base status and plasma acetate concentrations were studied in eight children during 11 hemodialysis sessions. During dialysis, the blood bicarbonate concentration fell (20.5 +/- 0.7 to 19.6 +/- 0.8 mEq/liter), the Pco2 fell (33.4 +/- 0.8 to 27.5 +/- 1.4 mm Hg), and the pH rose (7.42 +/- 0.01 to 7.48 +/- 0.02). During the hour after dialysis, the bicarbonate concentration rose to normal (23.4 +/- 0.7 mEq/liter), the PCO2 rose (32.8 +/- 0.8 mm Hg), and the pH remained unchanged. The half-life of plasma acetate, measured after dialysis, was 8.7 min. During five "high-efficiency" dialysis sessions (urea clearance, greater than 3.0 ml/min/kg), blood bicarbonate concentration fell 3.2 mEq/liter, PCO2 fell 8.7 mm Hg, and plasma acetate rose to 7.51 mmoles/liter, whereas during six "routine efficiency" dialysis sessions (urea clearance. 1.5 to 3.0 ml/min/kg), blood bicarbonate rose 1.0 mEq/liter, PCO2 fell 36 mm Hg, and plasma acetate rose to 3.52 mmoles/liter. At 1 hour after the end of dialysis, blood bicarbonate, PCO2, and plasma acetate concentrations were similar in the two groups. Clinical problems occurred more frequently in the high-efficiency group during dialysis although the difference was not significant. The data indicate that (1) dialysis with acetate buffer effectively corrects predialysis metabolic acidosis, (2) although children have a high rate of acetate metabolism, during high-efficiency dialysis this rate is exceeded by the influx of acetate, and acid-base abnormalities occur. These abnormalities are transient but may cause clinical problems.

Acetates↗
PubMed1997

Effects of acetate on energy metabolism and function in the isolated perfused rat heart.

Impairment of cardiac contractile function is an important component of acetate associated hypotension during hemodialysis treatments. We examined the effect of acetate on cardiac energy metabolism using the isovolumic isolated perfused heart model. In this preparation, acetate (10 M) caused decreases in tissue ATP concentrations (12.3 +/- 0.8 vs. 15.6 +/- 1.0 micromol/g dry at 30 min, P < 0.05) as well as marked impairment of systolic function (dpdt = 863 +/- 135 vs. 1288 +/- 166 mm Hg/second at 30 min, P < 0.05). Although altering perfusate calcium concentrations (0.6, 1.2 and 2.4 mM) affected physiological responses to acetate (5 and 10 mM), the reductions in tissue ATP concentrations were similar. In isolated heart mitochondria, acetate (100 microM -10 mM) selectively impaired octanoate and palmityl carnitine supported State 3 respiration in a dose dependent fashion (P < 0.01), but did not affect respiration when succinate, pyruvate/malate or malate/glutamate was used as substrate. We suggest that high concentrations of acetate selectively impair fatty acid metabolism in heart issue. This in turn leads to decreases in ATP production and tissue ATP concentrations that ultimately result in impaired contractile function. As this occurs at relatively low concentrations of acetate, this finding may be relevant to other parenterally-administered acetate containing fluids.

Acetates↗
PubMed2001

Effects of acetic acid and lactic acid on the growth of Saccharomyces cerevisiae in a minimal medium.

Specific growth rates (mu) of two strains of Saccharomyces cerevisiae decreased exponentially (R2 > 0.9) as the concentrations of acetic acid or lactic acid were increased in minimal media at 30 degrees C. Moreover, the length of the lag phase of each growth curve (h) increased exponentially as increasing concentrations of acetic or lactic acid were added to the media. The minimum inhibitory concentration (MIC) of acetic acid for yeast growth was 0.6% w/v (100 mM) and that of lactic acid was 2.5% w/v (278 mM) for both strains of yeast. However, acetic acid at concentrations as low as 0.05-0.1% w/v and lactic acid at concentrations of 0.2-0.8% w/v begin to stress the yeasts as seen by reduced growth rates and decreased rates of glucose consumption and ethanol production as the concentration of acetic or lactic acid in the media was raised. In the presence of increasing acetic acid, all the glucose in the medium was eventually consumed even though the rates of consumption differed. However, this was not observed in the presence of increasing lactic acid where glucose consumption was extremely protracted even at a concentration of 0.6% w/v (66 mM). A response surface central composite design was used to evaluate the interaction between acetic and lactic acids on the specific growth rate of both yeast strains at 30 degrees C. The data were analysed using the General Linear Models (GLM) procedure. From the analysis, the interaction between acetic acid and lactic acid was statistically significant (P < or = 0.001), i.e., the inhibitory effect of the two acids present together in a medium is highly synergistic.

Acetic Acid↗
PubMed1996

Treatment of nodular hepatocellular carcinoma larger than 3 cm with ultrasound-guided percutaneous acetic acid injection.

To assess the efficacy of ultrasound-guided percutaneous acetic acid (15%, 20%, 30%, 40%, and 50% in concentration) injection for a large nodular hepatocellular carcinoma (HCC), percutaneous acetic acid injection was performed using 15% to 50% acetic acid in 28 patients who had one single nodular HCC larger than 3 cm or one main tumor with fewer than two HCCs smaller than 3 cm during the past 7.5 years; the main tumor was slightly hypervascular in nine patients and was highly hypervascular, showing viable cancer cells despite transcatheter arterial embolization in 19 patients. During the series of treatment sessions for each patient, the same concentration of acetic acid was used. Eight (89%) of nine slightly hypervascular main tumors, 18 (95%) of 19 highly hypervascular main tumors, and all 14 small tumors were treated successfully. No serious complications occurred as a direct sequela to acetic acid injection. The 1-, 2- and 3-year recurrence rate from the original main tumor was 0%, 20%, and 20%, respectively, in patients treated with percutaneous acetic acid injection alone and 12%, 24%, and 24% in patients treated with percutaneous acetic acid injection after transcatheter arterial embolization (P = NS). The 1-, 2-, 3-, 4-, and 5-year survival rates were 100%, 80%, 80%, 80%, and 0%, respectively, in the former and 90%, 81%, 81%, 61%, and 61% in the latter (P = NS). Percutaneous acetic acid injection (15% to 50%) may be an effective therapy for slightly hypervascular nodular HCCs larger than 3 cm and highly hypervascular nodular HCCs larger than 3 cm that remain partly viable after transcatheter arterial embolization.

Acetic Acid↗
PubMed1986

[Inhibition of ovulation with 35 micrograms of ethinyl estradiol and 2 mg of cyproterone acetate (Diane 35)].

In the study reported here the ovulation inhibition dose for cyproterone acetate was determined. Experiments showed that the ovulation inhibition dose is 1 mg of cyproterone acetate, administered daily. Results proved that the cyproterone acetate dose cannot be reduced when cyproterone acetate is combined with ethinyl estradiol. However, the objective of this study was to determine whether it is possible to reduce the estrogen dose to 35 micrograms when the common combination of 2 mg cyproterone acetate and ethinyl estradiol is being used. After a control menstruation cycle, 2 mg cyproterone acetate and 35 micrograms ethinyl estradiol were administered daily to six women with normal menstruation. Drug administration began on Day 5 and ended on Day 25. During the control cycle, the first treatment cycle, and the third treatment cycle, LH, FSH, 17 beta estradiol, progesterone, testosterone, prolactin, and SHGB were examined daily. Cervix score and karyopyknosis index were determined at the same time. In addition, antithrombin III was examined during the control cycle and during the third treatment cycle. Present results show that ovulation inhibition is possible with dose reduction of ethinyl estradiol to 35 micrograms, combined with 2 mg of cyproterone acetate. Increase in SHBG and reduction in testosterone serum level point to an additional antiandrogenic effect of cyproterone acetate, aside from its cellular effect. The combined preparation discussed here does not bring about any changes in antithrombin III values. Results permit the conclusion that ovulation inhibition is insured with a reduction of the daily estrogen dose from 50 micrograms to 35 micrograms.

Adult↗
PubMed1989

Lupins and energy-yielding nutrients in ewes. II. Responses in ovulation rate in ewes to increased availability of glucose, acetate and amino acids.

An experiment, using a total of 320 Merino ewes, over two successive breeding seasons was conducted to investigate the separate effects of energy-yielding and protein-yielding nutrients on ovulation rate in sheep. The available energy-yielding or protein-yielding nutrients in the blood of sheep fed a maintenance pelleted ration were increased by either intravenous infusions of metabolites (acetate, glucose or acetate + glucose), feeding lupin grain, modification of the pattern of rumen fermentation to increase propionate production using the ionophore, lasalocid, or by feeding of ruminally undegradable protein (formaldehyde-treated casein). All treatments were given for 9 days prior to and including expected time of ovulation. Ovulation rates were measured by laparoscopy. In the first season (the 1984 experiment) when the effects of lupin grain, glucose + acetate and formaldehyde-treated casein were compared, ovulation rates were increased significantly in the group fed lupin (29%, P less than 0.001) and the group infused with glucose + acetate (24%, P less than 0.01). There was an apparent (17%) but statistically non-significant increase in the group fed casein. In comparisons between lupin grain, glucose, acetate, glucose + acetate, formaldehyde-treated casein and lasalocid in the 1985 experiment there were similar significant increases in ovulation rates in the groups fed lupin, and those infused with glucose or glucose + acetate (approximately 25%, P less than 0.001). The increase in the group infused with acetate was lower at 14% (P less than 0.05) and the increases of 7% in the groups fed casein or lasalocid were not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1982

Acetate metabolism in lactating sheep.

1. The metabolism of acetate, glucose and D(-)-3-hydroxybutyrate was studied in lactating and non-lactating sheep in vivo. Special consideration was given to the utilization by hind-limb muscle in both groups of sheep and the uptake of nutrients by the lactating mammary gland was also measured. 2. The entry of acetate into the circulation (mmol/h per kg body-weight) was similar in all experimental animals at a given arterial concentration of acetate. However, normal lactation was associated with a reduced extraction of acetate by muscle and the 'spared' acetate was comparable with that removed by the udder. Feeding lactating ewes a 700 g concentrate/kg ration tended to prevent this redistribution of acetate utilization. 3. The muscles of non-lactating ewes utilized sufficient glucose, when corrected for lactate release, to account for 57% of the oxygen utilization by muscle. In lactation this fell to 32% largely because of an increased lactate production. D(-)-3-Hydroxybutyrate utilization by muscle accounted for 16-17% of the O2 consumed by the muscle in non-lactating and lactating sheep. 4. Lactating mammary gland metabolism in sheep was similar to published values for dairy cows and goats. Thus the extraction (%) of glucose, O2, acetate and D(-)-3-hydroxybutyrate was 25, 28, 62 and 53 respectively. Blood flow was 529 ml/min per kg udder and the ratio, blood flow: milk flow was 475. glucose used by the udder relative to the whole animal utilization rate may be less in sheep than in cows and goats, but the comparable proportion for acetate is as large or larger than in these species.

3-Hydroxybutyric Acid↗
PubMed2005

Formulation and process parameters affecting protein encapsulation into PLGA microspheres during ethyl acetate-based microencapsulation process.

The objective of this study was to investigate formulation and process parameters affecting protein encapsulation into PLGA microspheres during an ethyl acetate-based double emulsion microencapsulation process. Lysozyme was used as a model protein throughout this study. An aqueous lysozyme solution was emulsified in ethyl acetate containing 0.6 approximately 1.2 g PLGA75 : 25. The primary emulsion was then transferred quickly to an aqueous phase to make a water-in-oil-in-water emulsion. Ethyl acetate quenching was performed on the double emulsion stirred for 5, 15, 30 or 45 min. The resultant microspheres were further hardened, collected and dried overnight under vacuum. The bicinchoninic acid assay was carried out to determine the quantity of lysozyme present in the aqueous continuous phase and inside the microspheres. While the primary emulsion was stirred without quenching, lysozyme in the inner water phase continued diffusing across the ethyl acetate phase into the aqueous continuous phase. Emulsion droplets were also broken into smaller ones with ongoing stirring; this event also contributed to lysozyme leaking out of the inner water phase. The amount of lysozyme leaching to the aqueous continuous phase ranged from 4.79 +/- 2.1 to 51.9 +/- 5.3% under the experimental condition. Ethyl acetate quenching stopped the primary emulsion droplets from being fragmented into smaller ones and caused PLA75 : 25 precipitation to form microspheres. As a result, the rate of ethyl acetate removal influenced lysozyme encapsulation efficiency, as well as microsphere size. Depending on the timing of ethyl acetate quenching, lysozyme encapsulation efficiencies were found to be 9.89 +/- 4.53 approximately 75.82 +/- 6.55%. Optimization of the onset of ethyl acetate quenching and formulations could permit attainment of a desirable protein encapsulation efficiency.

Acetates↗
PubMed1978

Comparison of acetate-1-14C metabolism in uremic and nonuremic dogs.

Acetate-1-14C was infused into six anephric uremic and six anephric nonuremic dogs during a 4-hr hemodialysis against a standard acetate containing (39.5 mM) dialysis solution. Arterial acetate (nonradioactive) levels achieved a steady state by the end of dialysis indicating that the maximum rate of acetate metabolism had not been exceeded. The mean arterial acetate level at the end of dialysis was 2.6 mM in both groups of dogs. Acetate disappearance after the cessation of dialysis followed first order kinetics with a mean half-life of 3.8 +/- 0.5 min in the uremic and 3.7 +/- 0.5 min in the nonuremic dogs. Most of the infused acetate-1-14C was metabolized to 14CO2 within 8 hr after dialysis. An average of 84 and 71% of the infused acetate-1-14C was metabolized to 14CO2 in the uremic and nonuremic dogs, respectively. Small but significant amounts of radioactivity were incorporated into lipids of plasma and other tissues. Incorporation of radioactivity into total lipids of liver, omental fat, and sciatic nerve was significantly greater in the uremic as compared to the nonuremic dogs. Incorporation of radioactivity into total lipids of heart, aorta, and plasma was the same in both groups of dogs.

Acetates↗
PubMed2004

L-Rhamnose increases serum propionate after long-term supplementation, but lactulose does not raise serum acetate.

BACKGROUND: Acute ingestion of the unabsorbed sugar l-rhamnose in humans raises serum propionate, whereas acute ingestion of lactulose raises serum acetate. It is not known whether short-chain fatty acid concentrations in urine and feces reflect those in blood. OBJECTIVE: The objective was to test the effects of oral l-rhamnose and lactulose for 28 d on acetate and propionate concentrations in serum, urine, and feces. DESIGN: Eleven subjects ingested 25 g l-rhamnose, lactulose, or d-glucose (control) for 28 d in a partially randomized crossover design. One fecal sample, hourly blood samples, and all urine samples were collected over 12 h on the last day of each phase. RESULTS: The increase in serum propionate was greater after l-rhamnose than after lactulose (P < 0.05). The effect of lactulose on serum acetate was not significant, but lactulose raised the acetate:propionate ratio compared with d-glucose or l-rhamnose in serum (P < 0.005) and urine (P < 0.02). Flatulence was significantly greater after lactulose and l-rhamnose than after d-glucose (P < 0.0001), an effect that lasted 4 wk with lactulose but only 1 wk with l-rhamnose. CONCLUSIONS: This study confirmed that l-rhamnose ingestion over 28 d continues to selectively raise serum propionate in humans. Although serum acetate did not increase significantly after lactulose, the serum acetate:propionate ratio was significantly different after l-rhamnose and lactulose, which suggests that these substrates could be used to examine the role of colonic acetate and propionate production in the effect of dietary fiber on lipid metabolism. Changes in the ratio of urinary acetate to propionate reflected those in serum.

Acetates↗
PubMed1987

Simulation of the metabolism of absorbed energy-yielding nutrients in young sheep: efficiency of utilization of acetate.

A previously described mathematical model that simulates the metabolism of absorbed nutrients was used to examine factors influencing the efficiency of utilization of acetate in a sheep weighing 25 kg. A significant component of the model was a function representing substrate cycles that degraded ATP when its concentration reached twice initial levels. Acetate utilization was simulated when up to 2 g mol/d were added to four diets (representing forages and concentrates) that supplied varying proportions of absorbed volatile fatty acids, glucose and protein. The basal diets provided either 4.375 (near energy balance) or 8.75 MJ/d absorbed energy. The predicted net efficiency of utilization (kf) of the energy in added acetate was high (0.58-0.70) for all combinations of absorbed nutrients at the low level of energy absorption, whereas at the higher level, it ranged from 0.16 (forage) to 0.49 (high protein concentrate). Low kf values were always associated with a considerable flux of ATP through the degradation pathway. The increase in ATP concentration that caused this pathway to operate was linked to an inhibition in the utilization of acetyl-CoA for fatty acid synthesis and an increase in its oxidation. The simulated addition of exogenous NADPH or its precursors (particularly glucose and propionate) to these diets repartitioned acetyl-CoA flux towards fatty acid synthesis instead of oxidation, decreased the flux of ATP through the degradation pathway and increased the kf of added acetate. Although a negative relationship was predicted between kf of added acetate and NADPH production for diets with increasing protein content, kf still depended on ATP flux through the degradation pathway. Addition of glucose to the high protein diets decreased this flux by decreasing acetyl-CoA oxidation and increasing fatty acid synthesis. The predictions suggest that the efficiency of acetate utilization in ruminants may be influenced by NADPH availability when a considerable amount of absorbed energy is derived from acetate. Increased absorption of glucose or propionate enhanced NADPH production, but the major effect on acetate utilization of increasing dietary protein was not through NADPH production.

Absorption↗
PubMed1989

Plasma ammonia, plasma, brain and liver amino acids and urea cycle enzyme activities in rats fed ammonium acetate.

Male Sprague-Dawley rats were trained to eat a 6% casein diet within a 3-h period each day. They were then fed a 6% casein diet for 10-16 d before they were fed either the same 6% casein diet or the 6% casein diet supplemented with 15% ammonium acetate for 1 or 7 d. During the absorptive period, plasma ammonia, plasma amino acids and brain amino acids were measured on d 1 and d 7 after feeding ammonium acetate. Food intake of rats fed 15% ammonium acetate was depressed on d 1 and increased to approximately 75% of the intake of the 6% casein-fed group by d 7. On d 1 plasma ammonia of the rats fed 5% ammonium acetate was 101 microM as compared to 56 microM for the rats fed 6% casein (P less than 0.05). On d 7, plasma ammonia of the rats fed 15% ammonium acetate was 240 microM (P less than 0.05) as compared to 44 microM for the rats fed 6% casein. In rats fed 15% ammonium acetate, after 7 d ornithine transcarbamylase and arginase activities were higher and argininosuccinate synthetase activity was lower (P less than 0.05) while carbamyl phosphate synthetase activity tended to be higher than that of rats fed 6% casein. The results suggest that rats adapt to ingestion of 15% ammonium acetate by some unknown neural mechanism rather than by increases in all urea cycle enzyme activities. Feeding ammonium acetate causes changes in plasma, brain and liver amino acid concentrations.

Acetates↗
PubMed2005

Colonic fermentation of inulin increases whole-body acetate turnover in dogs.

Metabolism of acetate from colonic fermentation was investigated in dogs. Beagle dogs (n = 9) were fed a control diet for 17 d followed by a 3% inulin-enriched diet (from chicory) for 4 and 21 d. On 3 occasions, the dogs were administered simultaneously infusions of [1-(13)C]acetate i.v. and [1,2-(13)C(2)]acetate intrarectally. Peripheral acetate concentration and turnover did not change over time after consumption of an inulin-enriched diet for 4 d. After 21 d of consuming the inulin-enriched diet, the whole-body acetate turnover increased significantly by 31% from (mean +/- SEM) 15.6 +/- 2.2 to 20.4 +/- 2.9 micromol/(kg . min) without a change in concentration. The rate of colonic acetate production that reached the peripheral circulation was 4.8 +/- 1.8 micromol/(kg . min). However, no [1,2-(13)C(2)]acetate tracer was recovered in the peripheral circulation. The fraction of oxidized tracer was higher in the gut (64 +/- 3%) than in peripheral circulation (46 +/- 3%) in dogs fed an inulin-enriched diet for 21 d. In conclusion, colonic fermentation of inulin occurred and indirectly stimulated whole-body acetate turnover in dogs fed an inulin-enriched diet for 21 d.

Acetates↗
PubMed1990

Controlled trial of megestrol acetate for the treatment of cancer anorexia and cachexia.

Preliminary information has suggested that megestrol acetate leads to appetite stimulation and nonfluid weight gain in patients with breast cancer, other cancers, and AIDS. Pursuant to this, we developed a randomized, double-blind, placebo-controlled trial of megestrol acetate in patients with cancer-associated anorexia and cachexia. We randomly assigned 133 eligible patients to receive 800 mg of megestrol acetate per day or a placebo. Patients assigned to megestrol acetate more frequently reported improved appetite (P = .003) and food intake (P = .009) when compared with patients receiving the placebo. A weight gain of 15 lb or more over baseline was seen in 11 of 67 (16%) patients receiving megestrol acetate compared with one of 66 (2%) given the placebo (P = .003). Patients receiving megestrol acetate reported significantly less nausea (13% vs. 38%; P = .001) and emesis (8% vs. 25%, P = .009). No clinically or statistically significant toxic reactions were ascribed to megestrol acetate, with the exception of mild edema. This study convincingly demonstrated that megestrol acetate can stimulate appetite and food intake in patients with anorexia and cachexia associated with cancer, leading to significant weight gain in a proportion of such patients.

Adult↗
PubMed1976

Cultural factors influencing the utilization or production of acetate by Butyrivibrio fibrisolvens.

Utilization of acetate by four strains of Butyrivibrio fibrisolvens was influenced by the composition of their growth medium. Growth-limiting glucose concentrations, low availability of CO2 and the presence of sodium lactate all stimulated acetate uptake by three strains. The type strain, D1, utilized acetate if the concentration of acetate added to the medium was at least 15 mumol ml-1. In batch culture, all strains produced acetate before entering a phase of acetate uptake. Continuous-culture studies with one strain showed that acetate uptake was dependent upon growth rate. The amount of n-butyrate produced in batch or continuous culture was closely linked to the amount of acetate taken up.

Acetates↗
PubMed1997

A double-blind randomised controlled trial of the effects of medroxyprogesterone acetate on bone density of women taking oestrogen replacement therapy.

OBJECTIVE: To assess the effects of medroxyprogesterone acetate on bone density in women who have had a hysterectomy. DESIGN: Randomised, double-blind, placebo-controlled trial of medroxyprogesterone acetate 10 mg, 20 mg or placebo as an adjunct to oestrogen therapy. PARTICIPANTS: One hundred and twenty-three women, aged 18 to 45 years and currently receiving daily oestrogen, who presented at a university-based rheumatology practice. INTERVENTIONS: The women were randomly assigned to receive either medroxyprogesterone acetate 10 mg, 20 mg or placebo daily beginning on day 15 of each month for one year. Forty-one women were randomised into each group. MAIN OUTCOME MEASURE: The primary outcome measurement was the percentage of change from baseline in bone mineral density of the lumbar spine (L2-L4). Secondary outcome measures included differences in femoral neck bone density, cholesterol and triglyceride levels between groups. RESULTS: At one year, change in bone mineral density did not differ between either the treatment or placebo groups. Medroxyprogesterone acetate 20 mg and 10 mg led to statistically significant reductions in very low density lipoprotein cholesterol, total triglycerides, and very low density lipoprotein triglycerides when compared with placebo. Medroxyprogesterone acetate 20 mg also led to a statistically significant reduction in high density lipoprotein cholesterol, high density lipoprotein-2 cholesterol, and high density lipoprotein-2 triglycerides. CONCLUSIONS: Medroxyprogesterone acetate at either dose as an adjunct to oestrogen did not improve bone mineral density at one year when compared with placebo. Medroxyprogesterone acetate 10 mg may not adversely affect lipids. Medroxyprogesterone acetate 20 mg, however, did reduce high density lipoprotein cholesterol and therefore may increase cardiovascular risk.

Adolescent↗