Critical analysis of article

Answer

Nature of study

The study is a controlled experiment by nature (Hulley, Cummings, Browner, Grady, & Newman, 2013). This is based on the fact that a set of experiments are conducted on the placebo and the treated participants under controlled environment of diet, body conditions and physical activity to determine the effect of the test drug combination on the treatment of obesity.

Aim of the study

This study aims to evaluate the pharmacotherapeutic efficacy of standardized extracts of G. Cambogia (52.4% HCA) plus A. Konjac(94.9% glucomannan) in the treatment of obesity.

Hypotheses of the study

Null Hypothesis: There is no significant pharmacotherapeutic efficacy of a combination of the standardized extracts of the stated percentages of G. Cambogia plus A. konjac in the treatment of obesity.

Alternate hypothesis: There is a significant pharmacotherapeutic efficacy of a combination of the standardized extracts of the stated percentages of G. Cambogia plus A. konjac in the treatment of obesity.

Methods

Participants

Participants in the study were drawn from RS; Brazil residents aged 25 to 60 years of age. The inclusion criteria used to sample the population included an individual with a BMI of 30 to 39 kg/m2 and not using any drugs that may affect their blood glucose, lipid profile, appetite and weight levels for the past eight weeks (Vasques et al., 2008). Similarly, the sample population must meet the following characteristics: have a constant physical activity level for the past six months, a stable weight with less than 4kg variation in the past three months, have stable eating habits, they are not on a diet to reduce calories, and have good health.

The study omitted pregnant and lactating mothers as well as individuals with a history of alcohol and drug use, dependent mental illness, laxative/bulimia use, hypothyroidism, gallstones, recurrent kidney stones, and cancer. Similarly, individuals suffering active gastrointestinal dysfunction, untreated high blood pressure, type 2 diabetes that is controlled using drugs, diabetes that is insulin dependent, liver dysfunction, chronic kidney disease, any weight reducing surgery and those that had quit smoking in the last six months were exempted from the study.

Other requirements for the study population included thyrotropin levels of 0.3 to 5.0 μUI/mL. Alanine aminotransferase levels of between 3 and 50 U/L, aspartate aminotransferase levels of between 12 and 46 U/L, alkaline phosphatase level not exceeding 300 U/L, and minimum creatinine levels of between 90 and 130 ml for male participants and 70to 115 ml for female participants.

The placebo treatment comprised of 26 individuals comprising of 21 female and five male participants while the test treatment group had 32 participants of which 25 were women and seven men (Vasques et al., 2008).

Materials

The main materials used in the study included 2.4g of Garcinia cambogia and 1.5 amorphophallus konjac extracts as capsules containing 500mg and 800 mg respectively.

Basic Procedure

According to Vasques et al. (2008), before starting the procedure, measurement or estimation of blood sugar and fasting lipid profile levels, resting energy expenditure and body composition were analyzed. This procedure was to be repeated every four weeks after commencing treatment.

Before any main meal; that is breakfast, lunch, and supper, the subjects of the study were instructed to take a capsule of each product. The drugs were to be taken thirty minutes before the meal three times a day (Vasques et al., 2008).

The patients were expected to report through survey and effects the drugs had on them. This way, the pharmacotherapeutic and nutritional data were obtained for sample selection and monitoring any changes in eating habits and physical exercise during the study period. The information is also useful to detect and monitor any negative effects the drugs may have on the population.

The body mass index and the waist/hip ratios were obtained from the measurement of weight, height, hip, and waist circumference. The body composition and resting energy expenditure were also estimated. Laboratory tests were also conducted on blood samples to measure the triglyceride, HDL-cholesterol, total cholesterol and fasting blood glucose levels. Similar laboratory tests were done to monitor possible impairment of the kidney or liver during the treatment period as well as measuring the creatinine and transaminase levels.

The results were statistically analyzed using the Kolmogorov-Smirnov tests to check for normal variation. The ANOVA and Student’s t-test was also used to check for deviations from the mean with a 0.005 confidence level (Vasques et al., 2008).

Findings

According to Bagchi & Preuss (2013), many therapies have been developed to counter obesity; most of which are lifestyle modifications. However, these undertakings may not be sufficient to reduce the body weight adequately. In such cases, it is important to include drugs that form part of the therapy. Commonly administered drugs include sibutramine and amphetamines that have negative side-effects on the central neurotransmission system that may cause cardiovascular disorders (Bagchi & Preuss, 2013). Due to these negative impacts, alternatives are constantly sought for drugs that will facilitate obesity treatment without causing negative effects to the body. Some of these alternatives include glucomannan fibers and hydroxycitric acid both of which are directly extracted from Amorphophallus konjac and Garcinia cambogia natural products (Lim, 2012).

32 participants in the treated group and 26 in the placebo group completed the treatment. Throughout the treatment plan, individuals from the placebo group reported the following symptoms: 4% headache, nausea, diarrhea, 11% constipation, abdominal pain, gastric acidity and 14% diuresis frequencies. Those in the treated group recorded symptoms rates as follows: 6% headache and gastric acidity, 9% diuresis, nausea, bloating and constipation and 13% abdominal pain (Vasques et al., 2008).

At the end of treatment, the resting calorimetric, anthropometric and phytotherapy parameters differed similarly for both placebo and treated groups. This means that their variation from the men at the start of the experiment was insignificant over the twelve weeks experiment period meaning that the drug ingredients are suitable for human consumption. However, given the short duration used in the experiment, it is unclear about the use of the drug combination for long-term weight loss programs. The joint administration does not affect the glucose, resting energy expenditure, or triglycerides levels as well as the anthropometric parameters. However, the total cholesterol is significantly reduced (Vasques et al., 2008).

Potential Threats to Validity

One of the fundamental principles of scientific research is that it has to be verifiable and objective. However, it is never without risks or potential threats. Usually, the threats are evident during the methodological stage.

Measurement Validity

Treatment artifacts present a threat to measurement validity. This is the case since the experiment uses practice effect where measurements are taken before the treatment commences. In such circumstances, the participants become sensitive to the study aims and may practice an opportunity that produces improved performance (Hulley, Cummings, Browner, Grady, & Newman, 2013).

Lack of reliability in the instrumentation is also a threat to measurement validity. This can result from using faulty instruments or instruments that have a big margin of error hence acquiring results that cannot be relied upon in research. Similarly, due to the nature of measurement change such as using a different person to conduct the pretest and posttest measurements can result in changes referred to as inter-rater reliability (Hulley, Cummings, Browner, Grady, & Newman, 2013).

Other measurement artifacts include the participants to the research participants giving strategic responses intended to help or challenge the researcher. Similarly, the research is faced with cultural bias where the experiment is performed on a specific region of Brazil. This makes the study limited in use by other races cultural orientations (Hulley, Cummings, Browner, Grady, & Newman, 2013).

Internal Validity

One of the threats to internal validity is the group composition effects. The selected group varies in age and gender. As a result, the effects of treatment could be obscured by the pre-existing group differences. Similarly, the behavior of the participants could change about age and sexual orientation. This can lead to changes in physical activity and diet levels and variation for individuals of different age and sex. Finally, the study states that some people dropped out of the study. However, it does not indicate the manner of leaving. An internal validity threat arises when the participants leave treatment systematically or selectively creating differences among groups that may obscure the independent variable’s effects (Hulley, Cummings, Browner, Grady, & Newman, 2013).

External Validity

Nonrepresentative sampling may be the cause of external validity in the research. This is the case where childhood obesity is not considered. Thus, the study only outlines the use of the drug combination for individuals of a selected age bracket which is not a representation of the general population (Hulley, Cummings, Browner, Grady, & Newman, 2013).

Suggestions on how to Resolve Threats to Validity

Threats to measurement validity can be resolved depending on the type. Instrumentation threats can be resolved by using the same instrument for pretest and posttest measurements and ensuring regular calibration to minimize errors of measurements. Similarly, the same person who conducts the pretest measurements should be the one conducting all measurements to avoid inter-rater reliability. The cultural bias can be overcome by undertaking the study using people from different races and cultural backgrounds to facilitate globally acceptable results.

Threats to group composition effects can be overcome by recording measurements of people from different age and sex separately and compiling results from the individual measurements and not as a group. Similarly, the behavior of the groups should be closely monitored to detect and record any variations. The study should also observe the manner in which participants drop out to ensure that it is as random as the research requires.

External validity is crucial in any research study. Therefore, to counter external threats, the researcher ought to use a sample that is a true representation of the general population. Individuals suffer obesity across the age bracket ranging from childhood obesity cases to the aged population. Therefore, the sample should include participants of all ages to arrive at a universal conclusion of the aim of the experiment.