Mannheim Obesity Study
Mannheim Obesity Study
MOPS: Mannheim Obesity Pilot Study

 Introduction:

 Obesity is a central feature of the metabolic syndrome. With increasing prevalence of
 overweight and obesity, the incidence of WHO III° obesity will further augment. In this
 subset of obese patients, metabolic complications and cardiovascular risk are major clinical
 issues. Epidemiological data show that with increased BMI mortality rises (1). The SOS-Study
 demonstrated, for the first time, that bariatric surgery and consecutive weight reduction are
 associated with a decrease in cardiovascular and overall mortality. Significant mortality in
 this study was caused by cardiovascular events and cancer.

 Metabolic Syndrome - MS - Despite varying definitions of the metabolic syndrome, obesity is
 one of its central features. Depending on the definition used, it can represent an obligate
 criterion (IDF) or a facultative parameter (WHO and ATP III). Even though not obligate,
 extreme obesity is a central risk factor for most other parameters of the metabolic syndrome.

 Endothelial dysfunction -ED- represents the initial step of atherosclerosis (3). An
 appropriate measurement is the evaluation by retinal analysis. Epidemiological data
 demonstrate increased cardiovascular risk with retinal vessel pathology (4).
Methods and procedures

 Study design:

 We conducted a prospective study in obesity WHO III° with consecutive enrollment. The study
 protocol was approved by the local ethics committee. Patients were recruited within an
 integrated concept designed for individuals seeking weight reduction. This network
 encompassed a complex approach by nutrition specialists, bariatric surgeons,
 endocrinologists, ENT specialists and psychologists. Patients could present themselves at any
 of the aforementioned specialists for study inclusion. Those who consented were followed,
 after conventional weight loss (diet, activity) or bariatric surgery 1 year later.

 Evaluation:

 Using a standardized form, we evaluated the medical and obesity history as well as associated
 metabolic complications (impaired glucose metabolism, elevated Cholesterol and NASH). We
 further inquired about regular medication, related diseases and classic cardiovascular risk
 factors (Framingham risk score: cardiovascular disease, family history of cardiovascular
 disease, nicotine abuse and arterial hypertension).

 Anthropometry - Subsequently, a complete physical examination was conducted, taking into
 consideration the use of an adequate cuff to measure blood pressure. We further recorded
 circumferences of the neck, arm and waist (midway between the lower rib margin and iliac
 crest, with a measuring tape at the end of gentle expiration). Body weight and height were
 determined by calibrated scales to the nearest 0.1kg and cm, respectively.

 Metabolism - Metabolic analysis was performed after an overnight fast. Baseline measurements
 included blood glucose, insulin, cholesterol, HDL, LDL, triglycerides and liver enzymes.
 Every individual without known diabetes was screened for the presence of impaired glucose
 metabolism by means of an OGTT. To exclude endocrine obesity we measured TSH levels and
 performed a one mg dexamethasone suppression test.

 Intima media thickness (IMT) - Measurement of the intima media thickness of the right carotid
 artery was performed in order to detect subclinical vascular disease. Imaging protocol was
 executed according to the consensus statement of the American Society of Echocardiography
 (5).

 Structural and functional endothelial dysfunction: Arterial and venous ratio (AVR) and
 flicker reaction - DVA was used for digital fundus imaging as well as conventional fundus
 examinations and retinal vessel analysis (RVA, imedos, Jena, Germany). Structural endothelial
 dysfunction was determined by arterial-venous ratio (AVR). After mydriasis with phenylephrine
 10% and tropicamide 1%, images centred on the macula, the inferior arcade and the optic disc
 were recorded in both eyes. AVR was calculated by software after marking arteries and veins
 within two diameters of the optic disc (RVA, imedos, Jena, Germany).

 Functional endothelial dysfunction was measured by flicker reaction of retinal vessels. This
 technique records dilatation of retinal vessels during and after exposure to flickering
 light. We used 1.5 mm segments of vessels within two disc diameters, which showed no crossing
 or bifurcation, and had a tortuosity < 30°. After baseline calibration, flickering light was
 shown for 20 seconds via interruption of continuous light at 12.5 Hz. During this period and
 for further 80 seconds, vessel diameter was continuously measured. To achieve higher
 reliability, this procedure was performed three times. Flicker of the artery and vein was
 expressed as the maximum in percent of the baseline diameter. Adjustment for eye movement was
 performed automatically by software. Details of this technique were published elsewhere
 (6-7).

 BIA - Body composition was determined preoperatively by BIA. All patients were required to
 rest for 30 minutes, after which BIA was performed by applying 4 silver electrodes, with 2
 detecting electrodes placed at the ulnar aspect of the right wrist and the right medial
 malleolus. After connecting the electrodes to the multiple-frequency BIA instrument (BIA
 2000, Data Input, Darmstadt, Germany), measurements were recorded in real time via computer.
 The calculations for BCM, ECM, ECM/BCM, fat and TBW were performed using Nutri 2000 software
 (Data Input, Darmstadt, Germany).

 Endpoints - The endpoint of our study was the identification of cardiovascular risk and
 metabolic complications or factors representing these risks in a population with obesity WHO.
 Therefore, we measured parameters of the metabolic syndrome, endothelial dysfunction and
 subclinical atherosclerosis. Patients, who gave informed consent, are followed after
 conventional weight loss (diet, activity) or bariatric surgery yearly. The decision for the
 type of intervention is connected to a complex process. According to the German obesity
 society subjects with more than 40 kg/m2 and patients with a BMI > 35 kg/m2 with obesity
 associated disease have the indication for bariatric surgery. After drafting of an expert's
 opinion for coverage of the costs by the health insurance patients may attend bariatric
 surgery. Because of the noncommittal character of the guideline of the German obesity society
 to health insurances not all patients will be able to get coverage for their surgery costs.
 Patients who are not able to get cost coverage or refuse surgery represent the conservative
 treatment (activity, diet). The interventional group will be treated by bariatric surgery
 (sleeve gastrectomy, Roux-en-Y gastric bypass). Therefore, the study has observational
 character.
Inclusion Criteria:

 -  obesity WHO I-III

 Exclusion Criteria:

 -  pregnancy

 -  acute vascular event within the last 3 months