Chronobiometric identification of disorders of hunger sensation in essential obesity: therapeutic effects of dexfenfluramine

The orexigram in patients affected by morbid obesity: a preliminary report on daily hunger sensation before bariatric surgery

OBJECTIVE

The present study investigated the orexigram, the time-qualified self-rated estimate of hunger sensation (HS), in patients affected by morbid obesity (MO) with the aim of detecting how daily HS behaves before morbidly obese patients (MOP) undergo bariatric surgery (BS). This article is therefore a preliminary report as it is necessary to make subsequent comparisons with post-BS orexigrams. Preoperative orexigrams may be helpful in selecting the MOPs who are candidates for surgical treatment.

MATERIALS AND METHODS

Ten MOPs (five males and five females, with a mean age of 34 +/- 11 yr and a mean BMI of 49.32 +/- 7.26 kg/m2), and 19 clinically healthy control subjects (CHS: nine males and ten females, with a mean age of 24 +/- 2 yr and a mean BMI of 21.00 +/- 1.70 kg/m2) gave their informed consent to participate in the study. All of the study participants were asked to compile a 24-h orexigram, which was then biometrically analysed by means of: 1) conventional methods for parametric statistics; 2) rhythm analysis for their circadian rhythms; and 3) spectral analysis for their harmonic structure.

RESULTS

The orexigrams of the MOPs had significantly increased mean daily levels (daily hyperorexia), retained their circadian periodicity despite an increase in mesor, and were consistently modified in their ultradian spectral harmonic components.

CONCLUSIONS

The results show that the studied MOPs complain of a daily hyperorexia that is still perceived circadically. This perception is a structured abnormality, as demonstrated by the consistent changes in the spectral analysis, and so MOPs can be diagnosed as being affected by so-called "hyperorectic obesity". It will be interesting to see whether or not presurgical hyperorexia in MOPs is corrected by BS: if so, hyperorexia may become an additional indication, and presurgery orexigrams could be suggested as an additional means of selecting the hyperorectic MOPs who are candidates for surgical treatment.

Circadian rhythm of hunger sensation in patients affected by cystic fibrosis

OBJECTIVE

The aim of this study was to investigate the daily pattern of hunger sensation (HS) in patients affected by a non-advanced form of cystic fibrosis (CF) in order to detect how the orectic stimulus (OS) behaves in fibrocystic patients (FP) who are obliged to eat frequently because of their pancreatic exocrine insufficiency.

MATERIALS AND METHODS

The study involved 27 out-patients (13 males and 14 females; mean age 18 +/- 4 years; mean BMI 18.77 +/- 2.17 kg/m2) with a non-advanced form of CF, and 19 clinically healthy subjects (CHS, 9 males and 10 females; mean age 24 +/- 2 years; mean BMI 21.00 +/- 1.70 kg/m2). The FP were used to eating frequent small meals between the three main meals of breakfast, lunch and dinner. All of the participants were asked to compile an "orexigram"' which was chrono-biometrically analysed by means of: 1) conventional statistical methods; 2) rhythmometric analysis of circadian rhythm (CR); and 3) spectral analysis of the harmonic structure substantiating the within-day variability of HS.

RESULTS

HS in FP had 1) a significantly increased daily mean level; 2) a well-established CR, with a significantly increased oscillatory mesor and amplitude; and 3) a modified orexigram power spectrum affecting the ultradian harmonic components.

CONCLUSIONS

Our results suggest that the orectic perception of CF patients is characterised by "daily hyperorexia", with the maintenance of HS CR. This condition seems to be a structured abnormality insofar as there are visible changes in the orexigram spectral resolution, particular in the ultradian harmonic components whose oscillatory frequency is responsible for the diurnal pattern of HS. The hyperorexia of the investigated FP indicates that their frequent small meals are not sufficient to satisfy their HS, which may cause a vicious circle leading to progressively disrupted mealtime behaviour.

Circadian rhythm of hunger sensation in obese patients: effects of a short-term, moderately hypocaloric diet with a substitutive meal

This investigation deals with the circadian rhythm (CR) of hunger sensation (HS) in obese patients before and after a four-week, moderately hypocaloric diet with a substitutive meal. The study was performed on 25 non-diabetic obese patients (5 males and 20 females, mean age: 39.7 +/- 7, mean BMI: 27.9 1.4 Kg/m2), whose obesity was not associated with impaired glucose tolerance (IGT), binge eating, nor endocrine diseases. Their daily HS profile (orexigram) was analysed chronobiometrically. The moderately hypocaloric diet with a substitutive meal reduced the daily HS by about 10% by the fourth week. This reduction was apparently due to a tonic and amplitude modulation of the HS CR and was not accompanied by its disruption. No conclusions, however, could be drawn with regard to its orectic and clinical effects beyond four weeks.

Daily hunger sensation monitoring as a tool for investigating human circadian synchronization

This study investigates within-day hunger sensation (HS) variability in Clinically Healthy Subjects Adapted to Living in Antarctica (CHSALA), as compared to their coeval subjects living in their mother country. The aim is to detect how the orectic stimulus behaves in those environmental conditions and occupational schemes, in order to investigate the individual synchronization to sleep-wake alternation and meal time schedule. HS was estimated via a self-rating score of its intensity on a Visual Analog Scale, repeating the subjective perception every 30 min, unless sleeping. The individual HS time-qualified scores (orexigram) were analyzed according to conventional and chronobiological procedures. The orexigrams of the CHSALA were seen to show a more cadenced intermittence during the diurnal part of the day, strictly related to the meal timing, and a preserved circadian rhythm as well. In addition, these orexigrams were resolved in a spectrum of harmonic components which indicated a subsidiary number of ultradian formants. These findings are convincing evidence that the individual orexigram may be used to investigate whether or not a single subject is synchronized to sleep-wake cycle, meal time schedule and socio-occupational routines, instead of using more complex and expensive techniques, involving automated equipments and biohumoral assays.

Anxiety, depression, hunger and body composition: III. Their relationships in obese patients

The present paper explores the relationships between anxiety, depression, hunger sensation and body composition in obese patients (OP). The aim is to detect whether or not there are abnormalities in these relationships in OP as compared to clinically healthy subjects (CHS). The study was performed on 22 CHS (2 M, 20 W; mean age = 24 +/- 2 years; mean body mass index = 21 +/- 2 kg/m2) and 48 OP (4 M, 44 W; mean age = 40 +/- 17 years; mean body mass index = 32 +/- 7 kg/m2). Anxiety and depression were found to be correlated, negatively, with the relative lean body mass, and, positively, with the fat body mass in OP but not in CHS. These findings corroborate the idea that anxiety and depression can reach an abnormal expression when obesity shows its worst loss in lean body mass and its highest expansion in adipocyte mass. As hunger sensation was found not to correlate with either anxiety or depression in OP, the opinion is expressed that the impairment of anxio-depressive integrity is a corollary of obesity rather than a primary affective disorder leading to obesity via an enhanced food intake.

Daily hunger sensation and body compartments: II. Their relationships in obese patients

Hunger sensation (HS) is a signal whose levels change during the 24-h day. The daily mean level of HS was correlated with the human body compartments, as investigated by bioelectrical impedance analysis, to detect the relationship between the orectic perception and both the free fat mass (FFM) and the fat body mass (FBM) in 22 clinically healthy subjects (CHS) (2 M, 20 W, BMI: 18.5-24.0 kg/m2) and 48 obese patients (OP) (4 M, 44 W, BMI: 25.2-54.7 kg/m2). In CHS, the daily mean level of HS correlated positively with the FFM and negatively with the FBM. These correlations were not present in OP. This lack of relationships between HS and the body compartments where energy is maximally consumed (i.e., the FFM) and maximally stored (i.e., the FBM) indicates that the orectic response to energy expenditure and the orectic inhibition to fat accumulation are feedback mechanisms which are impaired in obesity.

Daily hunger sensation and body composition: I. Their relationships in clinically healthy subjects

The human hunger sensation (HS) is a perceptive signal characterized by day-night variability (DNV). This pattern was investigated with respect to its relations with the body compartments in 22 clinically healthy subjects (CHS, 11 males and 11 females, mean age: 24 +/- 2.5 years, mean BMI: 21 +/- 1.7). The DNV was investigated by means of conventional descriptive statistics and the single cosinor method (SCM). Both procedures were applied to the orexigram, i.e., the 24-h profile of the orectic stimulus (OS) provided by each subject, who self-rated his/her HS (from 1 to 10 hunger units) every half hour. Body composition was investigated by Bioelectrical Impedance Analysis (BIA) on the day when the orexigrams were compiled. It was found that the daily HS level correlates positively with the Free Fat Body Mass (FFBM) and negatively with the Fat Body Mass (FBM). These opposite relations indicate that HS is stimulated by the needs of the FFBM, and inhibited by expansion of the FBM, and provide further evidence of the existence of an "adipostat" anorectic mechanism.

Hunger sensation: a chronobiometric approach to its within-day and intra-day recursivity in anorexia nervosa restricting type

Hunger sensation (HS) is a perception with a daily (circadian) and within-day (ultradian) recursive pattern. In human beings, circadian repeatability was investigated by means of the Single Cosinor method, while the ultradian recursivity was investigated by means of the spectral analysis, both applied to the 24-h HS profile (orexigram). Orexigrams were provided by each subject investigated, who self-rated her subjective orectic stimulus (OS) (from 1 to 10 hunger units) every half hour. The study was performed in 19 female patients aged 13-52 newly diagnosed as in the first episode of Anorexia Nervosa Restricting Type, with a BMI below 18.7. The control group consisted of 10 clinically healthy women aged 21 to 52 years with a BMI from 23 to 25. Two types of orexigrams were found. The first was characterized by a low profile with negligible ultradian variability, in which the HS circadian rhythm (CR) was still detectable, but the power spectrum (PS) was composed of unusual ultradian components associated with a very diminished amplitude for the circadian harmonics. The second was characterized by an almost regular profile, in which the ultradian variability was clearly detectable, the CR regularly fluctuated, and the PS was almost regularly composed. These findings indicate that anorectic patients (AP) can be recognized by their orexigram as "hyporectic", or "eurectic". Therefore, the term "anorexia" seems to be appropriate for AP who exhibit the first type of orexigram (anorectic aphagia nervosa), whereas the second identifying those who could be defined as suffering from "eurectic aphagia nervosa".

Twenty-four-hour pattern of hunger sensation in obesity complicated by type 2 diabetes mellitus: a pattern recognition by spectral analysis

Hunger sensation (HS) in humans physiologically shows intraday (circadian) and within-day (ultradian) recursivity. This intrinsic periodicity was investigated by applying the cosinor method and spectral analysis to the 24-hour profile of HS (orexigram) derived by a self-rating score (from 1 to 10 hunger units [HU]) recorded every half-hour. The study of circadian and ultradian recursivity on the orexigram was performed in 30 diabetic obese patients ([DOPs], 14 men and 16 women aged 22 to 62 years; body weight, 77 to 130 kg; body mass index, 31-47). The control group consisted of 30 clinically healthy subjects ([CHS], 15 men and 15 women aged 21 to 60 years; body weight, 65 to 72 kg; body mass index, 23 to 25). DOPs showed two types of orexigrams in which hunger was felt with limitation to the diurnal part of the day or with extension to the night, respectively. The type 1 orexigram was characterized by a normal spectrum and circadian rhythm. The type 2 orexigram was characterized by subsidiary ultradian components associated with an abnormal elevation of the circadian mesor and a significant delay of the circadian phase, as the spectral analysis was indicative of a structural difference in the frequencies that sustain the intraday and within-day recursivity of the HS. Accordingly, DOPs can be recognized by their orexigram as "eurectic" or "hyperrectic" to indicate subjects with a normal or an exaggerated HS, respectively, during the 24-hour span.