Bariatric surgery has become an effective treatment for obesity, also reducing the onset of type 2 diabetes mellitus (T2DM) [
Obesity is a chronic condition characterized by elevated inflammatory markers [
Bariatric surgery improves steatosis and fibrosis in patients with morbid obesity NAFLD [
The aim of this study was to assess changes, if any, in morbidly obese patients treated with BPD-DS and RYGBP, from baseline, that is, before surgery, to followups 1 year and 3 years after surgery, with regard to platelet counts and serum concentrations of GGT and ALT.
Ten morbidly obese patients who had undergone BPD-DS surgery (five men and five women), all Caucasians, free from established diabetes, were recruited from the Outpatient Clinic of Obesity Care, Uppsala University Hospital, Uppsala, Sweden [
Roux-en-Y gastric bypass is a procedure that combines restriction and malabsorption. It is considered by many to be the gold standard because of its high level of effectiveness and its durability. More extreme malabsorption accompanies biliopancreatic diversion procedures, commonly performed with a duodenal switch in which a short, distal and common channel length of small intestine severely limits caloric absorption, which induces a greater weight loss than RYGBP does [
All participants underwent physical examination and blood tests for platelet count, GGT, and ALT preoperatively (baseline) and at the 1st and 2nd followups. Blood samples were collected from each patient (following an overnight fast) and were analyzed using routine tests at the Department of Clinical Chemistry at Uppsala University Hospital [
Weight (kg) and height (m) were measured on standardized calibrated scales, and BMI (kg/m2) was calculated.
All analyses were defined a priori. Results are presented as arithmetic means, with standard deviations. ANOVA was used to investigate trends over the 3 years of followup. Changes between different time points were analyzed using paired
Patient clinical characteristics at baseline, that is, before RYGBP and BPD-DS surgeries, are shown in Table
Clinical characteristics at baseline for patients, preoperatively to RYGBP and BPD-DS surgery and 1 and 3 years of followup after surgery.
RYGBP baseline | BPD-DS baseline | RYGBP | BPD-DS | RYGBP | BPD-DS |
|
|
---|---|---|---|---|---|---|---|
1 year | 1 year | 3 years | 3 years | ||||
Gender (women/men) | 18/3 | 5/5 | 18/3 | 5/5 | 18/3 | 5/5 | — |
Age (years) | 45.7 (9.7) | 37.0 (6.5) | — | — | — | — | 0.017 |
Height (cm) | 168.4 (6.2) | 173.0 (10.1) | — | — | — | — | 0.119 |
Weight (kg) | 120.0 (16.4) | 161.3 (26.7) | 84.0 (13.6) | 92.9 (21.4) | 90.8 (16.0) | 91.9 (25.8) | <0.001 |
BMI (kg/m2) | 42.3 (5.2) | 53.5 (3.8) | 29.7 (4.6) | 30.7 (4.6) | 32.1 (5.3) | 30.2 (5.0) | <0.001 |
Platelet counts (×109/L) | 297 (58) | 308 (55) | 266 (44) | 240 (40) | 292 (64) | 244 (56) | 0.645 |
P-GGT ( |
0.65 (0.42) | 0.87 (0.71) | 0.28 (0.19) | 0.39 (0.30) | 0.31 (0.24) | 0.32 (0.30) | 0.334 |
P-ALT ( |
0.62 (0.25) | 0.79 (0.39) | 0.34 (0.18) | 0.43 (0.18) | 0.24 (0.10) | 0.41 (0.13) | 0.154 |
Data shown are arithmetic means (±SD).
BMI: body mass index, GGT: gamma-glutamyltransferase, ALT: alanine aminotransferase, and P: plasma.
BMI decreased by 43% in the BPD-DS group from 53.5 kg/m2 at baseline to 30.7 kg/m2 at 1st followup (
The changes in BMI (a), platelet counts (b), and concentrations of gamma-glutamyltransferase (GGT) (c) are shown at baseline, that is, before surgery, at the 1st followup (1 year), and at the 2nd followup (3 years). Group symbols are as follows: morbidly obese patients treated with Roux-en-y gastric bypass surgery,
Platelet counts were reduced by 22% in the BPD-DS group from
GGT was markedly lowered by 55% in the BPD-DS group from 0.87
ALT was reduced by 46% in the BPD-DS group from 0.79
The main findings in this study were that liver enzymes, GGT and ALT, markedly decreased over time after both RYGBP and BPD-DS surgeries, but platelet counts only decreased significantly after BPD-DS. The alteration in platelet counts showed a somewhat different pattern after RYGBP, with a reduction at the 1st followup but no significant change at the 2nd followup. It might be speculated that the sustained reduction in platelet counts may indicate a long-term improvement in the inflammation of the liver and a more pronounced decrease of liver-fat-content-related inflammation in obese patients treated by BPD-DS compared to RYGBP. Platelets vary daily and are depending on a variety of issues such as ethnicity, age, and gender. However, longitudinal studies demonstrate considerable stability of steady-state platelet counts. Buckley et al. have showed in their analysis of serial platelet counts from 3,789 subjects that the repeatability of the platelet count is very high [
There are several limitations in the present study such as the small number of patients and the lack of a morbidly obese control group followedup over 3 years. However, such patients can be logistically difficult to follow for long term followups. The BPD-DS group was significantly younger than the RYGBP group, but no differences were observed between the two groups at baseline in platelet counts, GGT or ALT. Body fat content and liver fat content, measured by imaging techniques such as dual energy X-ray absorptiometry or ultrasonography, would have been warranted to investigate if and how different fat distribution might influence the variables analyzed in this study.
In conclusion, morbidly obese patients treated with RYGBP and BPD-DS show a marked and sustained decrease in GGT and ALT. A significant reduction in platelets, a marker for inflammation and fibrosis in NAFLD, was observed in both groups after 1 year but only in BPD-DS over time, which may indicate improvements in general inflammatory status and particularly steatohepatitis. However, extended studies are needed to confirm our findings.
The authors declare that they have no conflict of interests.
Funding was received by research grants from the Thureus Fund, the Thuring Family Foundation, and the Department of Obesity, Skönvikt, Landstinget Dalarna. Results and views of the presented study represent the authors and not necessarily any official views of the Swedish Medical Products Agency where one of the authors (B. Zethelius) is employed.