Application of Artificial Neural Networks (ANN) to Elucidate the Connections among Smell, Obesity with Related Metabolic Alterations, and Eating Habit in Patients with Weight Excess

Qualitative and Quantitative Sex-Related Differences in the Perception of Single Molecules from Coffee Headspace

One of the still-debated topics regarding the olfactory function concerns the presence or absence of sex-related differences in individuals. In this study, we checked for a relationship between the olfactory function of females and males and their ability to perceive single molecules, and researched how this can influence the intensity with which the complex odor formed by a set of single molecules is perceived. First, females and males were classified as normosmic or hyposmic based on the TDI olfactory score obtained using the Sniffin' Sticks test. Subsequently, the headspace of roasted coffee beans, as a complex olfactory stimulus, was broken down into single molecules by means of a chromatographic column; these were simultaneously conveyed to a mass spectrometer (for their subsequent classification) and to the human nose, which acts as a chemical sensor by means of an olfactometer port. The results obtained with this gas chromatography-olfactometry approach show both qualitative and quantitative differences between females and males, with females performing better than males. In addition, the odor intensity reported by females when sniffing pen #10, containing coffee aroma, is significantly higher than that reported by males. In conclusion, these data highlight that the human ability to perceive both single compounds and complex odors is strongly conditioned, not only by the olfactory function of individuals, but also by their sex.

Mediterranean Diet adherence, physical activity level, and quality of life in patients affected by thyroid diseases: Comparison between pre- and post-lockdown assessment

Background

SARS-CoV-2 pandemic resulted in lifestyle change of world's population because of the measures adopted by governments to contain the virus spread.

Design and Methods

This study examined whether lockdown impacted anthropometric indices, Mediterranean Diet (MD) adherence, Physical Activity Level (PAL), and Quality of Life (SF-12) in a cohort of 116 patients (96 F, aged 57.2 ± 13.1 years) affected by thyroid disorders. Before lockdown, data were collected during the endocrinological examination; after lockdown they were collected through a tele-phone interview (via video call).

Results

Data revealed an overweight condition in 59% of patients, with no significant differences between the two observations (BMI values: 26.5 ± 4.9 vs 26.6 ± 4.9 kg/m2), whereas waist circumference values significantly increased over time (93.3 ± 12.6 vs 94.4 ± 12.5 cm; p = 0.003). Moreover, a lower adherence to the MD (PREDIMED score: 7.3 ± 1.8 vs 7.0 ± 1.8; p = 0.003) and a significant increase of sitting time (6.4 ± 3.2 h/die vs 9.0 ± 4.2; p < 0.001) were observed. A not significant decrease in PAL, which revealed a sedentary condition in pre- and post-lockdown (648 and 562 METs/week respectively), was found. The SF-12 score did not show relevant changes between the two observations.

Conclusion

Our study highlights that patients with thyroid diseases are often sedentary and exhibit a high prevalence of over-weight, underscoring the need for a systematic anthropometric evaluation and, at times, lifestyle interventions.

Relationship between the Mediterranean Diet and Metabolic Syndrome and Each of the Components That Form It in Caucasian Subjects: A Cross-Sectional Trial

The main objective of this work is to investigate the relationship between the Mediterranean diet (MD) and metabolic syndrome (MetS) and its components in Caucasian subjects between 35 and 74 years. The secondary objective is to analyze sex differences.

METHODS

A cross-sectional trial. This study utilized data from the EVA, MARK, and EVIDENT studies, and a total of 3417 subjects with a mean age ± SD of 60.14 ± 9.14 years (57% men) were included. We followed the five criteria established in the National Cholesterol Education Program III to define MetS. The MD was assessed with the 14-item Mediterranean diet adherence screener (MEDAS) used in the PREDIMED study. Good adherence was considered when the MD value was higher than the median value.

RESULTS

The mean ± SD value of the MEDAS questionnaire was 5.83 ± 2.04 (men 5.66 ± 2.06 and women 6.04 ± 1.99; p < 0.001). Adherence to the MD was observed by 38.6% (34.3% men and 40.3% women; p < 0.001). MetS was observed in 41.6% (39.0% men and 45.2% women; p < 0.001). In the multiple regression analysis, after adjusting for possible confounders, the mean MD value showed a negative association with the number of MetS components per subject (β = -0.336), and with the different components of MetS: systolic blood pressure (β = -0.011), diastolic blood pressure (β = -0.029), glycemia (β = -0.009), triglycerides (β = -0.004), and waist circumference (β = -0.026), except with the HDL-cholesterol value which showed a positive association (β = 0.021); p < 0.001 in all cases. In the logistic regression analysis performed, we found that an increase in MD adherence was associated with a decrease in the probability of MetS (OR = 0.56) and its components: blood pressure levels ≥ 130/85 mmHg (OR = 0.63), fasting plasma glucose ≥ 100 mg/dL (OR = 0.62), triglyceride levels ≥ 150 mg/dL (OR = 0.65), waist circumference levels ≥ 88 cm in women and ≥102 cm in men (OR = 0.74), and increased high-density lipoprotein cholesterol < 40 mg/dL in men and <50 mg/dL in women (OR = 1.70); p < 0.001 in all cases. The results by sex were similar, both in multiple regression and logistic regression.

CONCLUSIONS

The results found in our work indicate that the greater the adherence to the MD, the lower the probability of presenting MetS. This result is repeated in the study by sex. More studies are needed to clarify that these results can be extended to the rest of the Mediterranean countries, and to other countries outside the Mediterranean basin.

Effect of the rs2821557 Polymorphism of the Human Kv1.3 Gene on Olfactory Function and BMI in Different Age Groups

The sense of smell plays an important role in influencing the eating habits of individuals and consequently, their body weight, and its impairment has been associated with modified eating behaviors and malnutrition problems. The inter-individual variability of olfactory function depends on several factors, including genetic and physiological ones. In this study, we evaluated the role of the Kv1.3 channel genotype and age, as well as their mutual relationships, on the olfactory function and BMI of individuals divided into young, adult and elderly groups. We assessed olfactory performance in 112 healthy individuals (young n = 39, adult n = 36, elderly n = 37) based on their TDI olfactory score obtained through the Sniffin' Sticks test and their BMI. Participants were genotyped for the rs2821557 polymorphism of the human gene encoding Kv1.3 channels, the minor C allele of which was associated with a decreased sense of smell and higher BMIs compared to the major T allele. The results show that TT homozygous subjects obtained higher TDI olfactory scores and showed lower BMIs than CC homozygous subjects, in all age groups considered. Furthermore, the positive effect of the T allele on olfactory function and BMI decreased with increasing age. The contribution of the genetic factor is less evident with advancing age, while the importance of the age factor is compensated for by genetics. These results show that genetic and physiological factors such as age act to balance each other.

The Role of the Olfactory System in Obesity and Metabolism in Humans: A Systematic Review and Meta-Analysis

Obesity, linked to chronic diseases, poses a global health challenge. While the role of the olfactory system in energy homeostasis is well-documented in rodents, its role in metabolism regulation and obesity in humans remains understudied. This review examines the interplay between olfactory function and metabolic alterations in human obesity and the effects of bariatric surgery on olfactory capabilities in humans. Adhering to PRISMA guidelines, a systematic review and meta-analysis was conducted, focusing exclusively on original human studies. From 51 articles, 14 were selected for the meta-analysis. It was found that variations in olfactory receptor genes influence the susceptibility to odors and predisposition to weight gain and poor eating habits. Bariatric surgery, particularly sleeve gastrectomy, shows significant improvements in olfactory function (SMD 2.37, 95% CI [0.96, 3.77], I = 92%, p = 0.001), especially regarding the olfactory threshold (SMD -1.65, 95% CI [-3.03, -0.27], I = 81%, p = 0.02). There is a bidirectional relationship between olfactory function and metabolism in humans. Bariatric surgery improves olfactory perception in obese patients, but it is still unclear if impacting the olfactory system directly affects eating behavior and the energy balance. However, these findings open novel avenues for future studies addressing the olfactory system as a novel target to alter systemic metabolism in humans.

BMI Increases in Individuals with COVID-19-Associated Olfactory Dysfunction

(1) Background: Reports suggest COVID-19-associated olfactory dysfunction (OD) may result in alterations in dietary behaviors and perceived weight change, but few studies using psychophysical evaluation of post-COVID-19-associated chemosensory dysfunction and body mass index (BMI) exist. The purpose of this study is to assess the impact of both quantitative and qualitative features of COVID-19-associated OD on BMI; (2) Methods: Recruitment of thirty-one participants with self-reported OD in the form of quantitative loss with and without qualitative features. Surveys with questions specific to qualitative olfactory function, Sniffin' Sticks tests, and BMI measures were completed at two visits, one year apart. Group differences were assessed with Wilcoxon signed-rank tests and the Holm-Bonferroni method; (3) Results: Individuals with persistent quantitative OD (n = 15) and self-reported parosmia (n = 19) showed statistically significant increases in BMI after 1 year (p = 0.004, adjusted α = 0.0125; p = 0.011, adjusted α = 0.0167). Controls with transient quantitative OD (n = 16) and participants without self-reported parosmia (n = 12) showed no statistically significant changes in BMI over the same time period (p = 0.079, adjusted α = 0.05; p = 0.028, adjusted α = 0.025); (4) Conclusions: This study shows an association between COVID-19-associated OD and BMI, suggesting olfaction may play a role in altering dietary habits and nutrition in this population. Larger study cohorts are needed to further evaluate this relationship.

The Implications of Taste and Olfaction in Nutrition and Health

Taste and olfaction are sensory modalities that act synergistically to orchestrate the behaviors essential for survival, such as interactions with the environment, nutrient-rich food identification, and the avoidance of noxious substances [...].