Reduced risk of liver-function-test abnormalities and new gallstone formation with weight loss on 3350-kJ (800-kcal) formula diets

Obese outbred mice only partially benefit from diet normalization or calorie restriction as preconception care interventions to improve metabolic health and oocyte quality

STUDY QUESTION

Can diet normalization or a calorie-restricted diet for 2 or 4 weeks be used as a preconception care intervention (PCCI) in Western-type diet-induced obese Swiss mice to restore metabolic health and oocyte quality?

SUMMARY ANSWER

Metabolic health and oocyte developmental competence was already significantly improved in the calorie-restricted group after 2 weeks, while obese mice that underwent diet normalization showed improved metabolic health after 2 weeks and improved oocyte quality after 4 weeks.

WHAT IS KNOWN ALREADY

Maternal obesity is linked with reduced metabolic health and oocyte quality; therefore, infertile obese women are advised to lose weight before conception to increase pregnancy chances. However, as there are no univocal guidelines and the specific impact on oocyte quality is not known, strategically designed studies are needed to provide fundamental insights in the importance of the type and duration of the dietary weight loss strategy for preconception metabolic health and oocyte quality.

STUDY DESIGN, SIZE, DURATION

Outbred female Swiss mice were fed a control (CTRL) or high-fat/high-sugar (HF/HS) diet. After 7 weeks, some of the HF mice were put on two different PCCIs, resulting in four treatment groups: (i) only control diet for up to 11 weeks (CTRL_CTRL), (ii) only HF diet for up to 11 weeks (HF_HF), (iii) switch at 7 weeks from an HF to an ad libitum control diet (HF_CTRL) and (iv) switch at 7 weeks from an HF to a 30% calorie-restricted control diet (HF_CR) for 2 or 4 weeks. Metabolic health and oocyte quality were assessed at 2 and 4 weeks after the start of the intervention (n = 8 mice/treatment/time point).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Changes in body weight were recorded. To study the impact on metabolic health, serum insulin, glucose, triglycerides, total cholesterol and alanine aminotransferase concentrations were measured, and glucose tolerance and insulin sensitivity were analyzed at PCCI Weeks 2 and 4. The quality of in vivo matured oocytes was evaluated by assessing intracellular lipid droplet content, mitochondrial activity and localization of active mitochondria, mitochondrial ultrastructure, cumulus cell targeted gene expression and oocyte in vitro developmental competence.

MAIN RESULTS AND THE ROLE OF CHANCE

Significant negative effects of an HF/HS diet on metabolic health and oocyte quality were confirmed (P < 0.05). HF_CTRL mice already showed restored body weight, serum lipid profile and glucose tolerance, similar to the CTRL_CTRL group after only 2 weeks of PCCI (P < 0.05 compared with HF_HF) while insulin sensitivity was not improved. Oocyte lipid droplet volume was reduced at PCCI Week 2 (P < 0.05 compared with HF_HF), while mitochondrial localization and activity were still aberrant. At PCCI Week 4, oocytes from HF_CTRL mice displayed significantly fewer mitochondrial ultrastructural abnormalities and improved mitochondrial activity (P < 0.05), while lipid content was again elevated. The in vitro developmental capacity of the oocytes was improved but did not reach the levels of the CTRL_CTRL mice. HF_CR mice completely restored cholesterol concentrations and insulin sensitivity already after 2 weeks. Other metabolic health parameters were only restored after 4 weeks of intervention with clear signs of fasting hypoglycemia. Although all mitochondrial parameters in HF_CR oocytes stayed aberrant, oocyte developmental competence in vitro was completely restored already after 2 weeks of intervention.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In this study, we applied a relevant HF/HS Western-type diet to induce obesity in an outbred mouse model. Nevertheless, physiological differences should be considered when translating these results to the human setting. However, the in-depth study and follow-up of the metabolic health changes together with the strategic implementation of specific PCCI intervals (2 and 4 weeks) related to the duration of the mouse folliculogenesis (3 weeks), should aid in the extrapolation of our findings to the human setting.

WIDER IMPLICATIONS OF THE FINDINGS

Our study results with a specific focus on oocyte quality provide important fundamental insights to be considered when developing preconception care guidelines for obese metabolically compromised women wishing to become pregnant.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Flemish Research Fund (FWO-SB grant 1S25020N and FWO project G038619N). The authors declare there are no conflicts of interest.

Diet normalization or caloric restriction as a preconception care strategy to improve metabolic health and oocyte quality in obese outbred mice

BACKGROUND

Maternal metabolic disorders are linked to reduced metabolic health and oocyte quality. Obese women are advised to lose weight before conception to increase pregnancy chances. However, as human studies show no univocal guidelines, more research is necessary to provide fundamental insights in the consequences of dietary weight loss on oocyte quality. Therefore, we investigated the impact of diet normalization or calorie restricted diet for two, four or six weeks, as preconception care intervention (PCCI), in obese mice on metabolic health and oocyte quality.

METHODS

Outbred female mice were fed a control (CTRL) or high-fat (HF) diet for 7 weeks (7w). Afterwards, HF-mice were put on different PCCIs, resulting in four treatment groups: 1) control diet up to 13w, 2) HF diet up to 13w (HF_HF), switch from a HF (7w) to 3) an ad libitum control diet (HF_CTRL) or 4) 30% calorie restricted control diet (HF_CR) for two, four or six weeks. Body weight, metabolic health, oocyte quality and overall fertility results were assessed.

RESULTS

Negative effects of HF diet on metabolic health, oocyte quality and pregnancy rates were confirmed. HF_CTRL mice progressively improved insulin sensitivity, glucose tolerance, serum insulin and cholesterol from PCCI w2 to w4. No further improvements in metabolic health were present at PCCI w6. However, PCCI w6 showed best oocyte quality improvements. Mature oocytes still showed elevated lipid droplet volume and mitochondrial activity but a significant reduction in ROS levels and ROS: active mitochondria ratio compared with HF_HF mice. HF_CR mice restored overall insulin sensitivity and glucose tolerance by PCCI w4. However, serum insulin, cholesterol and ALT remained abnormal. At PCCI w6, glucose tolerance was again reduced. However, only at PCCI w6, oocytes displayed reduced ROS levels and restored mitochondrial activity compared with HF_HF mice. In addition, at PCCI w6, both PCCI groups showed decreased mitochondrial ultrastructural abnormalities compared with the HF_HF group and restored pregnancy rates.

CONCLUSIONS

Diet normalization for 4 weeks showed to be the shortest, most promising intervention to improve metabolic health. Most promising improvements in oocyte quality were seen after 6 weeks of intervention in both PCCI groups. This research provides fundamental insights to be considered in developing substantiated preconception guidelines for obese women planning for pregnancy.

A Randomized Controlled Trial of the Effects of an Almond-enriched, Hypocaloric Diet on Liver Function Tests in Overweight/Obese Women

Background:

Gradual weight reduction has been shown to be associated with improvements in liver enzymes. However, some evidence demonstrated that liver enzymes may transiently increase immediately after a diet-induced weight loss.

Objectives:

This study was designed to assess the effects of a hypocaloric, almond-enriched diet (AED) compared with a hypocaloric nut-free diet (NFD) on liver function tests in the context of a three-month weight reduction program in overweight/obese women.

Patients and Methods:

This randomized controlled clinical trial was registered at Iranian Registry of Clinical Trials with ID number of IRCT2013062313751N1. Overweight and obese Iranian women [n = 108; age = 42.7 y, body mass index = 29.6 kg/m²] were randomly assigned to consume an AED or NFD. The carefully planned hypocaloric diets were identical for both groups except for the AED group who consumed 50 grams of almonds daily for three months. Anthropometric measurements and laboratory measurements including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) were assessed before and immediately after the intervention.

Results:

Of 108 participants, 50 women in AED group and 50 women in NFD group completed the protocol of the study (response rate: 92.6 %). The AED led to a median weight loss of 3.79 kg (interquartile range: 4.4 kg). Significant decreases within AED and NFD were observed in ALT (-16.6 ± 16.3 and -11.7 ± 16.8, P < 0.001, respectively). Similar significant decreases were observed in AST (-13.6 ± 15.7 and -7.7 ± 16.1; P < 0.001, respectively). The decrease in GGT was also significant in both groups (-11.4 ± 21.6 and -6.2 ± 19.8; P < 0.001 respectively). ALT, AST and GGT decreased significantly in the AED group compared to the NFD group (P < 0.001).

Conclusions:

AED improved liver enzymes in obese women. However, mild, transient increases in ALT and AST values can be observed immediately after an NFD in women.

Risk of symptomatic gallstones and cholecystectomy after a very-low-calorie diet or low-calorie diet in a commercial weight loss program: 1-year matched cohort study

Background:

Concern exists regarding gallstones as an adverse event of very-low-calorie diets (VLCDs; <800 kcal per day).

Objective:

To assess the risk of symptomatic gallstones requiring hospital care and/or cholecystectomy in a commercial weight loss program using VLCD or low-calorie diet (LCD).

Design:

A 1-year matched cohort study of consecutively enrolled adults in a commercial weight loss program conducted at 28 Swedish centers between 2006 and 2009. A 3-month weight loss phase of VLCD (500 kcal per day) or LCD (1200–1500 kcal per day) was followed by a 9-month weight maintenance phase. Matching (1:1) was performed by age, sex, body mass index, waist circumference and gallstone history (n=3320:3320). Gallstone and cholecystectomy data were retrieved from the Swedish National Patient Register.

Results:

One-year weight loss was greater in the VLCD than in the LCD group (−11.1 versus −8.1 kg; adjusted difference, −2.8 kg, 95% CI −3.1 to −2.4; P<0.001). During 6361 person–years, 48 and 14 gallstones requiring hospital care occurred in the VLCD and LCD groups, respectively, (152 versus 44/10 000 person–years; hazard ratio, 3.4, 95% CI 1.8–6.3; P<0.001; number-needed-to-harm, 92, 95% CI 63–168; P<0.001). Of the 62 gallstone events, 38 (61%) resulted in cholecystectomy (29 versus 9; hazard ratio, 3.2, 95% CI 1.5–6.8; P=0.003; number-needed-to-harm, 151, 95% CI 94–377; P<0.001). Adjusting for 3-month weight loss attenuated the hazard ratios, but the risk remained higher with VLCD than LCD for gallstones (2.5, 95% CI 1.3–5.1; P=0.009) and became borderline for cholecystectomy (2.2, 95% CI 0.9–5.2; P=0.08).

Conclusion:

The risk of symptomatic gallstones requiring hospitalization or cholecystectomy, albeit low, was 3-fold greater with VLCD than LCD during the 1-year commercial weight loss program.

Assessment of gallstone predictor: comparative analysis of ultrasonographic and biochemical parameters

Background

Gallstones represent a significant burden for health care systems worldwide and are one of the most common disorders presenting to emergency room. Ultrasonography, complete blood picture test and liver function tests are procedures of choice in suspected gallstones or biliary diseases. They are the most sensitive, specific, non-invasive and inexpensive tests for the detection of gallstones. Our main objective was to evaluate the relationship of ultrasonographic findings, hemolytic indices and liver function tests with gallstones.

Methodology

It was a prospective study carried out in Civil Hospital Karachi (DUHS) and Liaquat National Hospital, two largest tertiary care hospitals of Karachi, Pakistan. Duration of the study was from July 2011 to October 2012. The study was carried out on diagnosed, pre-operative and symptomatic patients of cholelithiases. Exclusion criteria were patients of gallbladder and pancreatic carcinoma, emergency operations, patients having age <12 years and non-cooperative patients, who refused to give written consent for participation in the study. Total two tests were performed on each patient after diagnosis by ultrasonography. These were complete blood count and liver function tests. All the demographic data, laboratory findings and ultrasonographic features were noted in a pre-structured Performa. Sample size was calculated by using open-epidemiological sample size calculator prevalence (p) = 35%, d = 5%, and confidence interval (CI) 95% = 350. All the data was entered and analyzed through SPSS 19.

Result

There were 454 diagnosed and pre-operative cases of gallstones present in the study. There were 120(26.4%) males and 334(73.6%) females, with a mean age of 42.80 ± 12.26 years. Most of the suspects had multiple stones 384 (84.5%) while few had single stones 70(15.4%). Fatty liver was found to be present in 144(31.7%) patients and 92(20.2%) had hepatomegaly. Splenomegaly was present in 16(3.5%) patients. Alkaline phosphatase was elevated in 186(41.0%) patients while SGPT was found to be raised in 160(35.2%). Blood urea nitrogen was found to be elevated in 186(41%) patients and serum creatinine was elevated in 46(10.1%) patients.

Conclusion

In the light of findings it is recommend that all patients should go through the process of ultrasonography and all the biochemical parameters should be analyzed before surgery.

Weight loss and dropout during a commercial weight-loss program including a very-low-calorie diet, a low-calorie diet, or restricted normal food: observational cohort study

BACKGROUND

The effectiveness of commercial weight-loss programs consisting of very-low-calorie diets (VLCDs) and low-calorie diets (LCDs) is unclear.

OBJECTIVE

The aim of the study was to quantify weight loss and dropout during a commercial weight-loss program in Sweden (Itrim; cost: $1300/€1000; all participants paid their own fee).

DESIGN

This observational cohort study linked commercial weight-loss data with National Health Care Registers. Weight loss was induced with a 500-kcal liquid-formula VLCD [n = 3773; BMI (in kg/m(2)): 34 ± 5 (mean ± SD); 80% women; 45 ± 12 y of age (mean ± SD)], a 1200-1500-kcal formula and food-combination LCD (n = 4588; BMI: 30 ± 4; 86% women; 50 ± 11 y of age), and a 1500-1800-kcal/d restricted normal-food diet (n = 676; BMI: 29 ± 5; 81% women; 51 ± 12 y of age). Maintenance strategies included exercise and a calorie-restricted diet. Weight loss was analyzed by using an intention-to-treat analysis (baseline substitution).

RESULTS

After 1 y, mean (±SD) weight changes were -11.4 ± 9.1 kg with the VLCD (18% dropout), -6.8 ± 6.4 kg with the LCD (23% dropout), and -5.1 ± 5.9 kg with the restricted normal-food diet (26% dropout). In an adjusted analysis, the VLCD group lost 2.8 kg (95% CI: 2.5, 3.2) and 3.8 kg (95% CI: 3.2, 4.5) more than did the LCD and restricted normal-food groups, respectively. A high baseline BMI and rapid initial weight loss were both independently associated with greater 1-y weight loss (P < 0.001). Younger age and low initial weight loss predicted an increased dropout rate (P < 0.001). Treatment of depression (OR: 1.4; 95% CI: 1.1, 1.9) and psychosis (OR: 2.6; 95% CI: 1.1, 6.3) were associated with an increased dropout rate in the VLCD group.

CONCLUSION

A commercial weight-loss program, particularly one using a VLCD, was effective at reducing body weight in self-selected, self-paying adults.

Effect of a dietary-induced weight loss on liver enzymes in obese subjects

BACKGROUND

Weight loss was shown to be associated with improvements in liver enzymes and improvements of nonalcoholic fatty liver disease. However, some evidence also shows that liver enzymes may transiently increase immediately after a dietary-induced weight loss.

OBJECTIVE

The aim was to assess the outcome of liver enzymes after a low-calorie diet (LCD) as well as during a follow-up period and to identify predictors for potential changes in these liver enzymes.

DESIGN

In this post hoc analysis of an existing database, liver enzymes were assessed before and immediately after a highly standardized soy-based meal replacement LCD providing 800 kcal/d, as well as 32 and 60 wk after the end of the LCD.

RESULTS

Data emanating from 147 obese subjects (104 women and 43 men) without known hepatic disease were included in this study. The LCD led to a median weight loss of 12.1 kg (range: 7.7-27.6 kg). In men, a significant decrease in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was observed immediately after the LCD, whereas, in women, these enzymes increased significantly, although mildly; however, this increase was transient. Sex was the only identifiable predictor of these changes in liver enzymes.

CONCLUSIONS

This study showed that mild, transient increases in ALT and AST values can be observed immediately after an LCD in women, but not in men. These changes are probably of multifactorial origin and may be considered as benign as long as they remain transient.

The evolution of very-low-calorie diets: an update and meta-analysis

OBJECTIVE

Very-low-calorie diets (VLCDs), providing <800 kcal/d, have been used since the 1970s to induce rapid weight loss. Previous reviews of the literature have disagreed concerning the relative efficacy of VLCDs vs. conventional low-calorie diets (LCDs) for achieving long-term weight loss.

RESEARCH METHODS AND PROCEDURES

We sought to update findings on the clinical use, safety, and efficacy of VLCDs and to perform a meta-analysis of randomized trials that compared the long-term efficacy of LCDs and VLCDs. Original research articles were retrieved by a Medline search and from prior reviews of VLCDs. Trials were included only if they were randomized comparisons of LCDs and VLCDs and included a follow-up assessment at least 1 year after maximum weight loss. Data were abstracted by both authors regarding: duration of VLCD, total length of treatment, attrition, short- and long-term weight loss, changes in weight-related comorbidities, and adverse effects.

RESULTS

Six randomized trials were found that met inclusion criteria. VLCDs, compared with LCDs, induced significantly greater short-term weight losses (16.1 +/- 1.6% vs. 9.7 +/- 2.4% of initial weight, respectively; p = 0.0001) but similar long-term losses (6.3 +/- 3.2% vs. 5.0 +/- 4.0%, respectively; p > 0.2). Attrition was similar with VLCD and LCD regimens.

DISCUSSION

VLCDs did not produce greater long-term weight losses than LCDs. In the United States, the use of liquid meal replacements as part of a 1000 to 1500 kcal/d diet may provide an effective and less expensive alternative to VLCDs. In Europe, VLCDs are used with less intensive medical supervision than in the United States, which reduces the cost of this approach.

Lipase inhibition by orlistat: effects on gall-bladder kinetics and cholecystokinin release in obesity

BACKGROUND

Obese subjects are at risk of developing gallstones as a result of the obese state and during weight reduction.

AIM

To study whether orlistat, by lipase inhibition, impairs gall-bladder emptying, thus further predisposing weight-losing obese subjects to gallstone formation.

METHODS

Patients entering a randomized clinical trial of 1 month of diet, followed by treatment with placebo, 3 x 60 mg orlistat or 3 x 120 mg orlistat, underwent gall-bladder emptying studies measured by ultrasound. Meal-induced cholecystokinin release and gall-bladder emptying were investigated at the start, at randomization and after 1 and 12 months.

RESULTS

One month of dieting did not change gall-bladder emptying and cholecystokinin release. After 1 month, placebo treatment resulted in a decreased fasting volume of 11%, compared with increases of 26% and 47% with 60 and 120 mg orlistat, respectively. Gall-bladder emptying increased by 9% with placebo and decreased by 15% and 53% with 60 and 120 mg orlistat, respectively. Fasting cholecystokinin values and cholecystokinin release decreased significantly in the orlistat group. After 1 year, a persistent but attenuated effect of orlistat on gall-bladder emptying and cholecystokinin release remained. Three of 40 patients developed gallstones, two on placebo with major weight loss and one on 60 mg orlistat.

CONCLUSIONS

One month of lipase inhibition by orlistat significantly impaired gall-bladder motility, which persisted to some extent after 1 year. Obese subjects with diabetes or hyperlipidaemia, who are more at risk of gallstones, should be followed carefully.

Gallbladder sludge: what is its clinical significance?

Biliary sludge is a mixture of particulate solids that have precipitated from bile. Such sediment consists of cholesterol crystals, calcium bilirubinate pigment, and other calcium salts. Sludge is usually detected on transabdominal ultrasonography. Microscopy of aspirated bile and endoscopic ultrasonography are far more sensitive. Biliary sludge is associated with pregnancy; with rapid weight loss, particularly in the obese; with critical illness involving low or absent oral intake and the use of total parenteral nutrition (TPN); and following gastric surgery. It is also associated with biliary stones with common bile duct obstruction; with certain drugs, such as ceftriaxone and octreotide; and with bone marrow or solid organ transplantation. The clinical course of biliary sludge varies. It often vanishes, particularly if the causative event disappears; other cases wax and wane, and some go on to gallstones. Complications caused by biliary sludge include biliary colic, acute cholangitis, and acute pancreatitis. Asymptomatic patients with sludge or microlithiasis require no therapy. When patients are symptomatic or if complications arise, cholecystectomy is indicated. For the elderly or those at risk from the surgery, endoscopic sphincterotomy can prevent recurrent episodes of pancreatitis. Medical therapy is limited, although some approaches may show promise in the future.

Pyruvate and hydroxycitrate/carnitine may synergize to promote reverse electron transport in hepatocyte mitochondria, effectively 'uncoupling' the oxidation of fatty acids

In a recent pilot study, joint administration of pyruvate, hydroxycitrate (HCA), and carnitine to obese subjects was associated with a remarkable rate of body-fat loss and thermogenesis, strongly suggestive of uncoupled fatty-acid oxidation. Hepatocytes possess an uncoupling mechanism--reverse electron transport--that enables fasting ketogenesis to proceed independent of respiratory control. Electrons entering the respiratory chain at the coenzyme Q (CoQ) level via FAD-dependent acyl coA dehydrogenase, can be driven 'up' the chain by the electrochemical proton gradient to reduce NAD+; if these electrons are then shuttled to the cytoplasm, returning to the respiratory chain at the CoQ level, the net result is heat generation at the expense of the proton gradient, enabling the uncoupled flow of electrons to oxygen. Pyruvate's bariatric utility may stem from its ability to catalyze the rapid transport of high-energy electrons from mitochondria to the cytoplasm, thus stimulating electron shuttle mechanisms. By enabling rapid mitochondrial uptake of fatty acids and thus disinhibiting hepatocyte ketogenesis, HCA/carnitine should initiate reverse electron transport: concurrent amplification of electron shuttle mechanisms by pyruvate can be expected to accelerate this reverse electron transport, thereby decreasing the electrochemical proton gradient. As a result, hepatocytes may be able to convert fatty acids to CO2 and heat with little net generation of ATP. These considerations suggest that it may be feasible to render hepatocytes functionally equivalent to activated brown fat, such that stored fat can be selectively oxidized in the absence of caloric restriction. Other measures which enhance the efficiency of hepatocyte electron shuttle mechanisms may increase the efficacy of this strategy.

Obesity Treatment: Examining the Premises

Five basic premises underlie the recommendation that obese persons should lose weight: (1) obesity is physically unhealthy; (2) in obese persons, weight loss improves physical health; (3) long-term weight loss is possible; (4) the benefits of weight loss exceed the costs; and (5) weight loss is superior to or can add incrementally to the effects of alternative methods of improving the health and happiness of obese persons. Although the data are occasionally ambiguous, they generally support these premises. Obesity apparently causes increased morbidity and decreased longevity, even after controlling for many plausible confounding factors. Clinical studies consistently show that weight loss reduces morbidity. No adequate data exist on which to evaluate the effects of weight loss on mortality among obese persons. Additional data are needed, but long-term weight loss seems possible, although such losses remain difficult to maintain. A crude estimate is that about 20% of obese persons who attempt to lose weight can achieve and maintain a clinically meaningful weight loss. The short-term health and psychologic costs of gradual weight loss are minor, manageable, and easily surpassed by the short-term health and psychologic benefits. Long-term effects of weight loss on mortality are difficult to judge, and further research is needed. Weight loss can add incrementally to the effects of alternative methods to improve health and happiness among obese persons. Thus, these "alternatives" are better termed "complementary approaches," and their use need not preclude attempts at weight loss. Finally, we provide several guidelines to help practitioners assist obese persons in making reasonable informed decisions about weight loss.